---
title: "CVE-2026-77242: MCP Atlassian - Server Side Request Forgery"
description: "MCP Atlassian < 0.22.0 contains a server-side request forgery caused by inconsistent DNS resolution in validate_url_for_ssrf and connection libraries, letting unauthenticated attackers access internal or metadata endpoints, exploit requires crafted URL with short-lived DNS."
url: https://panop.io/threat-heartbeat/CVE-2026-77242/
---

# CVE-2026-77242 MCP Atlassian - Server Side Request Forgery

MCP Atlassian < 0.22.0 contains a server-side request forgery caused by inconsistent DNS resolution in validate\_url\_for\_ssrf and connection libraries, letting unauthenticated attackers access internal or metadata endpoints, exploit requires crafted URL with short-lived DNS.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

Proof of concept available

Authentication

Not required

EPSS

0.30% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-77242)

## Details

Type

Server Side Request Forgery

Impact

Server Side Request Forgery, Information Disclosure

CVSS vector

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

Published

22 September 2026

Updated

15 October 2026

Weakness

[CWE-367](https://cwe.mitre.org/data/definitions/367.html)

## Vendor fix

Update to version 0.22.0 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-77242](https://nvd.nist.gov/vuln/detail/CVE-2026-77242)
- [https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460](https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460)
- [https://github.com/sooperset/mcp-atlassian/pull/1448](https://github.com/sooperset/mcp-atlassian/pull/1448)
- [https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0](https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0)
- [https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-72fm-whvq-jghf](https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-72fm-whvq-jghf)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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