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Advisory record · GHSA-2xj6-xx86-cwwc

MCP Atlassian: Arbitrary File Read & Exfiltration (Confused Deputy) in JIRA update_issue

CVSS 8.6 HighEPSS 0.0046 · 39th percentile

Published by the GitHub Advisory Database at 22 Sept 2026, 20:34 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
mcp-atlassianPyPI<0.22.00.22.0
Identifiers
GHSA-2xj6-xx86-cwwc · CVE-2026-77255 · PYSEC-2026-4080
Weakness (CWE)
CWE-22 · CWE-441
Tags
Published
22 Sept 2026
Updated
1 Oct 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

The mcp-atlassian Python package, versions before 0.22.0, is vulnerable through the attachments parameter of the JIRA update_issue tool, which passes file paths directly to the Jira upload without validation. An attacker who can make an AI agent call this tool, such as through a sandboxed agent, can cause the server to read arbitrary host files, including its environment secrets, and attach them to a Jira issue. Upgrade to version 0.22.0 or later.

Written 1 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
8.6 High 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0046, the 39th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:09 UTC First seen by agentprime
  2. 31 Oct 2026, 14:09 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.