Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
High, CVSS 8.3amended

MCP Atlassian: Arbitrary local file READ via unconstrained file_path in upload_attachment (Confluence + Jira)

CVE-2026-77260GHSA-f4p7-qx46-wc5j

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (mcp-atlassian 0.22.0), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS 4.0
8.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N · score source
EPSS
  • CVE-2026-77260: 0.39% estimated exploitation activity in the next 30 days; percentile 32.61 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Summary This is an arbitrary local file READ vulnerability on the Confluence and Jira uploadattachment tool paths. It's the symmetric counterpart of the file-write vulnerability you patched as CVE-2026-27825. The write direction was fixed; the read direction was left open. Reporter: Sean Valentine Severity: High (Critical in LLM-driven / prompt-injection deployments) Affected versions: main branch as of 2026-04-21. Both Confluence and Jira upload paths. Details File: src/mcpatlassian/confluence/attachments.py lines 62-78 and 477 Same shape in src/mcpatlassian/jira/attachments.py around lines 374-386. validatesafepath() was added to the download paths as the CVE-2026-27825 fix, but the symmetric upload paths were never updated. os.path.abspath() alone does not restrict the result to any safe base directory, so absolute paths like /etc/shadow, /root/.ssh/idrsa, or ~/.aws/credentials are opened and uploaded verbatim. The Jira updateissue tool exposes the same primitive via its…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 4 · amended ·

    Amended from ghsa record GHSA-f4p7-qx46-wc5j

  2. Revision 3 · amended ·

    Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

  3. Revision 2 · amended ·

    Amended from osv record GHSA-f4p7-qx46-wc5j

  4. Revision 1 · created ·

    Published from ghsa record GHSA-f4p7-qx46-wc5j

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-77260

Advisory: MCP Atlassian: Arbitrary local file READ via unconstrained file_path in upload_attachment (Confluence + Jira)
IDs: CVE-2026-77260, GHSA-f4p7-qx46-wc5j
Record: https://patchnext.com/advisories/cve-2026-77260 (revision 4, source checked 26 Oct 2026, 13:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: mcp-atlassian 0.22.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI mcp-atlassian: affected < 0.22.0; fixed in 0.22.0

## Suggested inspection (read-only)
- `python -m pip show mcp-atlassian`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on mcp-atlassian.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-f4p7-qx46-wc5j (GitHub-reviewed advisory GHSA-f4p7-qx46-wc5j lists affected ranges: PyPI mcp-atlassian >=0 <0.22.0)
- Verified: https://osv.dev/vulnerability/GHSA-f4p7-qx46-wc5j (OSV record GHSA-f4p7-qx46-wc5j lists affected ranges: PyPI mcp-atlassian >=0 <0.22.0 (fixed))

Commands are suggestions: review each one before running it.

Loading voting…