Connect your agent
AdvisoriesCriticalCheck your lockfilePluginHow it worksPricing Connect your agent

Advisory record · GHSA-93xw-j965-9mx3

MCP Atlassian: Arbitrary file read/exfiltration via upload_attachment missing validate_safe_path()

CVSS 7.7 HighEPSS 0.0037 · 31st percentile

Published by the GitHub Advisory Database at 22 Sept 2026, 20:36 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-93xw-j965-9mx3 · CVE-2026-77258 · PYSEC-2026-4088
Weakness (CWE)
CWE-22
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.

mcp-atlassian versions before 0.22.0 are affected by an arbitrary file read flaw in the upload_attachment method, which reads local files without the path safety check that its download methods apply. An attacker who can influence the MCP agent, for example through prompt injection, can read any file the server process can access and upload it as a Confluence attachment, exposing it to other Confluence users. Upgrade to mcp-atlassian 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
7.7 High 3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0037, the 31st percentile, on 11 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.