Feed/GHSA-489g-7rxv-6c8q
GHSA-489g-7rxv-6c8qMEDIUMCVSS 6.5

MCP Atlassian: DNS-rebinding TOCTOU bypass of the SSRF fix (CVE-2026-27826)

Published Jul 10, 2026·Updated Jul 10, 2026

NVD Description

### Summary GHSA-7r34-79r5-rcc9's fix added `validate_url_for_ssrf`, which resolves the attacker-controlled `X-Atlassian-{Jira,Confluence}-Url` header host **once at middleware time** and trusts the result. But the outbound request is later built with the **raw hostname** and **re-resolves at connect time with no IP pinning**. An attacker-controlled rebinding DNS name returns a public IP on the guard's lookup (validation passes) and `169.254.169.254` / an internal IP on the request's lookup (the socket connects there) → unauthenticated SSRF to cloud metadata / internal services on the **patched** build. ### Relationship to CVE-2026-27826 / GHSA-7r34-79r5-rcc9 (incomplete fix — please read first) This is an **incomplete-fix sibling** of the published `GHSA-7r34-79r5-rcc9` (the `X-Atlassian-*-Url` header SSRF). That fix (PR #986/#1005) added a single middleware-time resolve + allowlist DNS-skip, but **does not pin the validated IP to the connection** — the fetcher re-resolves the raw hostname at connect time, so the documented SSRF mitigation is incomplete against DNS-rebinding. The other advisory `GHSA-xjgw-4wvw-rgm4` (file-write) is unrelated. Verified live (2026-06-27): neither advisory, nor any open PR/issue (`rebind`/`TOCTOU`/`getaddrinfo`/`pin` → 0), covers connect-time re-resolution. Filing as an incomplete-fix of GHSA-7r34 (not a standalone fresh SSRF). ### Affected `src/mcp_atlassian/utils/urls.py` + `servers/main.py` + `servers/dependencies.py`, HEAD `ba72540` (PyPI `mcp-atlassian`, patched ≥0.17.0). **CWE-918** (SSRF) via **CWE-367** (TOCTOU). ### Vulnerable code `utils/urls.py` `validate_url_for_ssrf` (≈184-205) resolves + validates, then returns a **string verdict, not a pinned IP**: ```python def validate_url_for_ssrf(url: str) -> str | None: # returns an error string or None — NO IP is pinned ... # resolves the host, checks each resolved IP is global, then DISCARDS the IP ``` `servers/main.py:526,534` calls it once in middleware. `servers/dependencies.py:544-561` then builds the fetcher with `url = <raw header hostname>` (no pinned IP, no custom resolver / cached-getaddrinfo adapter), so the actual request re-resolves the name. ### PoC (executed — boundary demonstration) The PoC loads the **real** `urls.py` by path (`importlib`, `sha256` printed) and drives the genuine `validate_url_for_ssrf`, simulating the two resolutions via `getaddrinfo`: ``` [CHECK ] validate_url_for_ssrf('http://rebind.attacker.example') -> None (getaddrinfo#1 = 93.184.216.34 global -> guard PASSED) [CONNECT] getaddrinfo call #2 returned 169.254.169.254 -> the socket connects HERE [PROOF ] guard validated IP 93.184.216.34 but connection targets 169.254.169.254 => SSRF on the PATCHED build [CONTROL] if guard SAW 169.254.169.254 at check time -> blocks it correctly [PIN ] validate_url_for_ssrf returns a verdict (None), NOT an IP; dependencies.py builds url=raw hostname -> NO pin ALL PoC ASSERTIONS PASSED — DNS-rebind TOCTOU bypass demonstrated. ``` **Honest scope of the PoC:** this is a **boundary** demonstration — it proves the structural TOCTOU (the guard validates an IP it then discards; the connection re-resolves an unpinned hostname). It does **not** demonstrate a live end-to-end SSRF on a running server; that additionally requires an attacker-controlled fast-rebinding authoritative DNS responder winning the resolve→connect window. Flagging this explicitly rather than overclaiming. ### Impact Same as parent GHSA-7r34 (unauth read of cloud-metadata IAM creds / internal-service reach), reachable again on the patched version. The `X-Atlassian-*-Url` headers are processed in `UserTokenMiddleware` before fetcher creation, so an unauthenticated/low-priv caller controls the host. ### Severity **High — CVSS v3.1 `AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N` ≈ 7.x**, aligned to the parent (8.2) with `AC:H` for the rebinding-race precondition. Honest caveat (above): the executed PoC proves the missing IP-pin structurally; a live exploit additionally needs an attacker rebinding-DNS. Not Critical. ### Remediation Pin the connection to the IP that `validate_url_for_ssrf` validated: use a custom resolver / cached-`getaddrinfo` `requests`-adapter (or pass the validated IP with a `Host` header), so the connect cannot re-resolve to a different address. ### Dedup / freshness (re-verified live 2026-06-27) Advisories `GHSA-7r34-79r5-rcc9` (original header SSRF this bypasses) + `GHSA-xjgw-4wvw-rgm4` (file-write, unrelated). Neither covers connect-time re-resolution / rebinding. PR [#986](https://github.com/sooperset/mcp-atlassian/pull/986)/[#1005](https://github.com/sooperset/mcp-atlassian/pull/1005) (the fix) add a single middleware-time resolve + allowlist DNS-skip, no pinning. `gh search prs/issues` for rebind/TOCTOU/getaddrinfo/pin → 0. First-party code. **Fresh** at HEAD `ba72540`.

Affected Packages (1)

mcp-atlassianPYPI
Fixed in 0.22.0

Public Exploits & PoCs100 found

PoC: CVE-2026-38192

pluck-CMS-4.7.20-code-injection-vulnerability

2

PoC: CVE-2026-62735

Windows HTTP.sys integer overflow -> nonpaged pool overflow LPE PoC (CVE-2026-62735): crash + full SYSTEM exploit; for authorized testing

1

PoC: CVE-2026-82329-JFrog-Artifactory-Auth-Bypass

CVE-2026-82329 — JFrog Artifactory (self-hosted) Auth Bypass

1

PoC: CVE-2026-65349

CVE-2026-65349 PoC — getattrlist OOB write in vfs_attr_pack_internal (iOS 26.6 / 23G71)

1

PoC: CVE-2026-65343

CVE-2026-65343 PoC — AppleKeyStore OOB read → KASLR defeat (iOS 26.6 / 23G71)

1

PoC: CVE-2026-65330

CVE-2026-65330 PoC — setxattr PAC bypass via fixed #0x307a diversifier (iOS 26.6 / 23G71)

1

PoC: CVE-2026-64788

CVE-2026-64788 PoC — IOGPUFamily Use-After-Free (iOS 26.6 / 23G71)

1

PoC: cve-2024-55591-poc

Educational implementation in Go for CVE-2024-55591 (Fortinet FortiOS Authentication Bypass). Designed for security research, vulnerability assessment, and understanding WebSocket-based auth bypass mechanisms.

1

PoC: cve-2026-82329-jfrog-artifactory

CVE-2026-82329 JFrog Artifactory unauthenticated auth-bypass: reproducible Docker lab + URL-parameter validator PoC + patch-diff analysis

1

PoC: CVE-2026-82592

D-Link DIR-825M formDiskFormat stack overflow + command injection RCE PoC (CVE-2026-82592); for authorized security testing

1

PoC: My-Exploits

Metasploit modules, Python PoCs and throwaway Docker labs for four platform CVEs: Keycloak (CVE-2026-18963), Apache NiFi (CVE-2026-39816), HashiCorp Vault (CVE-2026-5006), HashiCorp Nomad (CVE-2026-7474).

1

PoC: CVE-2025-66478-PoC-Reverse-Shell

CVE-2025-66478 PoC

1

PoC: cve-writeups-and-pocs

CVE-2026-80724 PoC + full write-up — Linux kernel ptp/vmclock read-only mapping becomes writable (VM_MAYWRITE). Discovered, reported & fixed by Abdifatah Suruur (suruurism)

1

PoC: CVE-2026-80428

CVE-2026-80428 PoC

PoC: gha-lab-b1fe4918c0

Authorized security-research lab: reproduction of CVE-2025-32958 (GHSA-8c7v-vccv-cx4q) — GITHUB_TOKEN leaked into workflow artifacts by Adept's remoteBuild.yml (snapshot of AdeptLanguage/Adept @ 6a64554)

PoC: CVE-2026-83548-SonicWall-SMA1000-Analysis

Vulnerability Analysis of CVE-2026-83548 affecting SonicWall SMA1000 security systems.

PoC: CVE-2024-21546

This repository contains security assessment tooling, detection templates, and an automated exploit toolkit for identifying and exploiting Unauthenticated Remote Code Execution (RCE) in applications utilizing the `UniSharp/laravel-filemanager` package (Versions `< 2.9.1`).

PoC: CVE-2026-78071

Stored XSS via Location Title in DPCalendar Free

PoC: CVE-2026-78070

SQL Injection via ORDER BY Shortcode in plg_content_dpcalendar — DPCalendar Free ≤ 10.11.2

PoC: CVE-2026-19949

CVE-2026-19949 - Draft or TODO

PoC: CVE-2026-59822

CVE-2026-59822 - Draft or TODO

PoC: struts2-tool

Struts2 S2-045/S2-046 CVE-2017-5638 detection & exploitation tool

PoC: gha-lab-becf103a54

Authorized security-research reproduction of CVE-2025-15617 (GHSA-6xqr-4q5g-xc7x): artipacked GITHUB_TOKEN leak in wazuh FIM Windows integration workflow artifacts

PoC: CVE-2025-9974

Proof of Concept code for the CVE-2025-9974 affecting Nokia Beacon routers.

PoC: tfo-connect-bypass

Bypassing connect()-based syscall rules using TCP Fast Open (CVE-2026-63828 PoC)

PoC: CVE-2026-38577-by-deepak-Anmol

CVE-2026-38577

PoC: gha-lab-23db52563c

Security-research lab: reproduction of CVE-2025-10894 (PR-title injection in GitHub Actions) — snapshot of nrwl/nx

PoC: CVE-2026-9335-keras-hdf5-externallink

CVE-2026-9335: KerasFileEditor and load_weights follow h5py ExternalLinks, disclosing arbitrary local HDF5 file contents in keras ≤ 3.14.0. Advisory + verified PoCs.

PoC: vsFTPd-2.3.4-Exploit

Python exploit for the vsFTPd 2.3.4 backdoor (CVE-2011-2523).

PoC: CVE-2026-73296

CVE-2026-73296

PoC: CVE-2026-19490

NetScaler ADC/Gateway SAML unsigned-assertion bypass via HTTP-Redirect binding (CTX696939) - root cause analysis + PoC

PoC: dast

CVE-2026-0828

PoC: SmarterMail-CVE-2026-24423-

Exploit for CVE-2026-24423 — a critical unauthenticated RCE in SmarterMail's ConnectToHub API. Affects all builds prior to 9511.

PoC: gha-lab-d9fd584b12

Authorized security-research lab reproducing CVE-2024-47179 (GHSL-2024-178): artifact-poisoning pwn-request chain in RSSHub docker-test workflows (snapshot at 574d053)

PoC: LAB1-metasploitable

Exploitation des vulnérabilités sur la version vsftpd 2.3.4 du service ftp (CVE-2011-2523)

PoC: CVE-2022-25765

CVE-2022-25765 | pdfkit v0.8.6 Python PoC

PoC: CVE-2026-7899

CVE-2026-7899 - Draft or TODO

PoC: gha-lab-6ab39df295

Controlled security-research lab reproducing CVE-2024-45798 (GHSA-h52q-xhg2-6jw8) in espressif/arduino-esp32 — poisoned-artifact pwn request via tests_results.yml workflow_run

PoC: CVE-2026-9586

CVE-2026-9586 - Draft or TODO

PoC: artifactory-CVE-2026-82329-poc.py

CVE-2026-82329 — JFrog Artifactory unauthenticated authentication bypass ("phantom join key" -> forged service admin token)

PoC: gha-lab-40e23db109

Security-research lab: controlled reproduction of CVE-2024-4254 (GHSA-fc78-c36r-cc59) — deploy-website.yml fork checkout/code execution in gradio-app/gradio @ d4c503a

PoC: root-s24-e1s

Galaxy S24 SM-S921B S921BXXSDCZB2 RAM-only KernelSU Next (CVE-2026-43499) + Root S24 app

PoC: CVE-2024-49138-SOC-Investigation

SOC investigation of CVE-2024-49138 exploitation involving brute-force activity, PowerShell execution, malicious payload analysis, privilege escalation, and incident response.

PoC: gha-lab-ee08e207a8

Authorized security-research lab reproducing CVE-2024-4253 (GHSA-r897-wrpm-h4vw): workflow_run command injection in gradio-app/gradio's test-functional.yml

PoC: CVE-2026-24061-Telnetd

CVE-2026-24061 GNU Inetutils Telnetd Authentication Bypass

PoC: Fortigate-SSL-VPN-Exploit-Kit

The FortiGate SSL-VPN pot of gold. CVE-2024-21762 and CVE-2023-27997. 79 working exploit clients. 53 hardware SKUs. 55 FortiOS builds.

PoC: CVE-2026-33017

CVE-2025-62593 — Ray Unauthenticated RCE Exploit is an unauthenticated remote code execution vulnerability in the Ray distributed AI compute engine.

PoC: CVE-2026-13753-poc

Poc of CVE-2026-13753

PoC: CVE-2026-82221

PoC for Unauthenticated Reflected Cross-Site Scripting (XSS) in RegistrationMagic WordPress Plugin

PoC: ActiveMQ-CVE-2023-46604

Exploit POC for Apache ActiveMQ CVE-2023-46604

PoC: gha-lab-0ba60e6456

Authorized security-research lab reproducing CVE-2024-39700 / GHSA-45gq-v5wm-82wg (JupyterLab extension-template update-integration-tests pwn request)

PoC: CVE-2026-36130

CVE-2026-36130

PoC: CVE-2026-31321

CVE-2026-31321

PoC: postgresql-cve-2026-14662

PostgreSQL の全文検索(tsvector/tsquery)に見つかった範囲外書き込み脆弱性 CVE-2026-14662 を、修正前(18.4)と修正後(18.6)を Docker で並べて動かして検証した記録と発表資料

PoC: CVE-2026-27472-and-CVE-2026-27474

PoC for CVE-2026-27472 and CVE-2026-27474

PoC: CVE-2026-27475

PoC for CVE-2026-27475

PoC: CVE-2026-18963

Unauthenticated account takeover via reset-credentials flow bypass

PoC: CVE-2026-0768

CVE-2026-0768 - Draft or TODO

PoC: CVE-2026-82329

CVE-2026-82329 - Draft or TODO

PoC: tomcat-line-check

CVE-2026-24880: does Apache's upgrade advice actually apply to your Tomcat? Detects the fix by class presence, not version comparison. Covers 7.0/8.0/8.5/9.0/10.0/10.1/11.0 lines.

PoC: tomcat85-check

CVE-2025-55752 CVE-2025-55754 CVE-2025-48988 CVE-2025-52520 CVE-2025-53506 CVE-2025-61795 CVE-2025-66614:Tomcat 8.5 已 EOL,终版 8.5.100。Apache 逐条声明「8.5 也受影响」的 2025 CVE 有 14 条,其中 10 条在 NVD 按 8.5.100 查不到。离线单 jar,读 conf/ 判断你到底中了哪几条。

PoC: log4j2-vuln-lab

CVE-2021-44228 (Log4Shell) 漏洞复现靶场 | SpringBoot + Log4j2 2.14.1 | 3 个攻击向量 PoC 验证

PoC: CVE-2021-3493-Exploit

It's a CVE-2021-3493 Exploit written in C

PoC: gha-lab-8e9316151c

Controlled security-research lab reproducing CVE-2024-1540 (GitHub Actions command injection in gradio-app/gradio deploy+test-visual.yml) — flattened snapshot of gradio-app/gradio @ f35f615e33a5dd90bfeb106b6f5dca689849fcef

PoC: gha-lab-6255f5fc33

Security-research lab reproducing CVE-2023-6572 (GHSA-gqvf-3hgp-5hxv): command injection in gradio-app/gradio's workflow_run handling of generate-changeset.yml

PoC: nextcloud-cve-2023-49792-research

A project analysis of CVE-2023-49792, inspired by a HackerOne report I have recently come across.

PoC: CVE-2026-30252

The ZenShare Suite application is vulnerable by a Reflected Cross-Site Scripting (XSS) vulnerability, affecting web application login and recovery password functionalities.

PoC: CVE-2026-30251

A reflected cross-site scripting (XSS) vulnerability in the login_newpwd.php endpoint of Interzen Consulting S.r.l ZenShare Suite v17.0 allows attackers to execute arbitrary Javascript in the context of the user's browser via a crafted URL injected into the codice_azienda parameter.

PoC: gha-lab-fb32aba4a3

Authorized lab reproduction of CVE-2023-26493 (GHSL-2023-027): command injection via github.head_ref in cocos-engine's <Web> Interface check pull_request_target workflow

PoC: CVE-2018-14667_Lab_POC

Demonstration of the expression language (EL) injection vulnerability CVE-2018-14667 using the photoalbum lab under Jboss application server

PoC: weakrng-sweep

Weak-RNG stream-sweep research (CVE-2026-71851 class): PRNG schemes x seeds -> BIP39 -> victim set membership

PoC: cve-2022-29117-assessment

CVE-2022-29117 (.NET Cookie-Handling DoS) Assessment, Understanding & Questions Framework

PoC: POC-CVE-2026-0073

Security research PoC for CVE-2026-0073: ADB authentication bypass verification

PoC: gha-lab-232af4821f

Security-research lab reproducing CVE-2021-4281 (GHSA-3796-3f93-cfvx): shell command injection via PR head-branch name in .github/workflows/combine-prs.yml (snapshot of BraveUX/for-the-badge @ 409c1fda). Do not use; authorized reproduction only.

PoC: CVE-2026-82222

GiveWP <= 4.16.7.1 Unauthenticated PHP Object Injection → RCE

PoC: CVE-2026-76569

Reflected XSS via search GET Parameter in Phoca Download

PoC: activemq-cve-lab

ActiveMQ CVE-2015-5254 模拟靶场 - 用于 CVE 测试评测和 SCA 扫描演示

PoC: ghostlock-x200-app

vivo X200 设备端一键 root App(Shizuku 授权 shell 域执行,CVE-2026-43499)

PoC: gha-lab-b9842b12c0

Authorized security-research lab reproducing CVE-2021-21423 (GHSA-gg2g-m5wc-vccq): projen rebuild-bot pwn request via issue_comment

PoC: gha-lab-e4a85583c3

Security-research lab reproducing CVE-2020-36762 (GHSA-h9gr-83jq-f3xc): bash command injection via github.event.comment.body in the comment workflow of ONSdigital/ras-collection-instrument

PoC: Root-My-Galaxy

KSU installer for supported Samsung Galaxy firmware with CVE-2026-43499

PoC: CVE-2026-78905-Facebook-Account-Takeover

Social Media Infrastructure Vulnerability Research. CVE-2026-78905: OAuth token reuse and session hijacking in Facebook's Graph API.

PoC: CVE-2026-78904-Digital-Dinar-Drain

CBDC Infrastructure Vulnerability Research. CVE-2026-78904: Infinite mint and redemption bypass in central bank digital currency APIs.

PoC: CVE-2026-78903-SWIFT-Kick-to-the-Creds

Offensive Research & Exploit Development. Vulnerability research, PoC development, and offensive tooling for financial infrastructure.

PoC: CVE-2026-60004-Gitea-RCE-PoC

🫖 Direct single-target Gitea CVE-2026-60004 RCE validation PoC

PoC: CVE-2026-60004-Gitea-Validator

🫖 Contract-correlated discovery and authorized validation tool for Gitea CVE-2026-60004

PoC: cve-2026-67363-67364

Balboa form Command Injection POC

PoC: Simulation-d-attaque-BlueBorne-sur-v-hicule-connect-

Simulation complète d'une attaque Bluetooth (CVE-2017-1000251) sur un véhicule autonome via CARLA Simulator ; exploitation de la vulnérabilité BlueBorne pour accéder au bus CAN et déclencher un freinage brutal, en environnement isolé (Kali Linux VM / VMware / Python).

PoC: CVE-2026-76581-Detector

Safe passive detector for identifying WPMU DEV Dashboard versions affected by CVE-2026-76581.

PoC: htb-machine-ringdown

Detailed design & exploitation writeup for Ringdown—an original Debian/Asterisk vulnerable machine featuring CVE-2024-42365 (AMI), PJSIP pre-hash cracking, and Fail2ban POSIX ACL privilege escalation.

PoC: gha-lab-83342297e0

Authorized security-research lab reproducing CVE-2024-41127 (GHSA-wcjf-5464-4wq9): poisoned pipeline execution via artifact-controlled code injection in ci-failure-comment.yml. Snapshot of monkeytypegame/monkeytype @ deeea0f.

PoC: WP2Shell-Scanner

Read-only CLI to check whether a WordPress site is exposed to WP2Shell (CVE-2026-63030 / CVE-2026-60137)

PoC: phpBB-CVE-2026-48611

Automated PoC for CVE-2026-48611 — phpBB OAuth login_link authentication bypass

PoC: Project-CVE-2026-45833

CVE-2026-45833 ChromaDB

PoC: CitrixBleedCVE-2026-8452-2025-5777

CitrixBleed Exploit Tool - CVE-2025-5777 & CVE-2026-8452. Unauthenticated remote memory read from Citrix NetScaler ADC & Gateway. Steal admin session tokens, extract nsroot hashes, dump secrets, and bypass MFA. Python 3 exploit with full memory parsing.

PoC: CVE-2026-76581

CVE-2026-76581

PoC: drupalgeddon2-cve-lab

Drupalgeddon2 CVE-2018-7600 vulnerable Drupal 7 lab

PoC: shellshock-cve-lab

Shellshock CVE-2014-6271 vulnerable CGI lab

PoC: log4shell-cve-lab

Log4Shell CVE-2021-44228 vulnerable lab

PoC: CVE-2026-18741

PoC CVE-2026-18741

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

References

View on NVD Search GitHub Search Google

Get alerted for CVEs like this

Register your stack and get notified within minutes when a matching CVE drops.

Start monitoring free