CVE-2026-77254

criticalpriority · track · 0OT risk · elevatedEPSS 0.006 · 49 %ileUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.62% (49th) EPSS

CVSS 9.1 · critical

Is it mine?

1 products

Check your exposure

Who says so?

1 sources

nvd

EPSS · scored 2026-10-27

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, requests to the HTTP MCP endpoint without a per-user identity are allowed to reach tool handlers, which then use globally configured Jira or Confluence credentials. A network caller can perform operations with the operator account's permissions unless the deployment has an independent authentication boundary. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, _get_fetcher, and global credentials, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

cvss

Technical severity, 0–10. One row per scoring source.

9.1

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.3–9.1

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · security-advisories@github.comexploitability 3.9 · impact 5.2

v3.18.3highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-306USprimary

affected products (1)

Products and version ranges known to be affected.

mcp-atlassian mcp atlassian< 0.22.0nvdUScpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:*

sources

Which sources assert this record, and when.

nvd NVD CVE.org MITRE

published 2026-09-22modified 2026-09-28

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+4460 more

references (4) nvd

External citations — patches, advisories, analysis.

https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460Patch
https://github.com/sooperset/mcp-atlassian/pull/1448Issue TrackingPatch
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0Release Notes
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hxExploitVendor Advisory

scry

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