Vulnerability details

CVE-2026-77261

sooperset mcp-atlassian

MCP Atlassian: SSRF redirect protection missing for basic-auth and OAuth authentication branches

CVSS 3.1

7.1High

Official description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, _make_ssrf_safe_hook is omitted from JiraFetcher and ConfluenceFetcher sessions created through the basic-auth and oauth_pat branches. If an attacker-controlled or compromised configured Atlassian instance returns a redirect to an internal address, those sessions can follow the redirect without revalidating its destination. This issue is fixed in version 0.22.0.

CVSS scores

Score	Version	Source	Vector
7.1High	3.1	CVEProject cvelistV5 (CNA) (GitHub_M)	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N`

Affected products

Vendor	Product	Versions	Source
sooperset	mcp-atlassian	< 0.22.0	CVEProject cvelistV5 (CNA)

References and advisories

https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-6529-c226-h328 x_refsource_CONFIRM
https://github.com/sooperset/mcp-atlassian/pull/1448 x_refsource_MISC
https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 x_refsource_MISC
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 x_refsource_MISC

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Details

Published: 2026-09-22
Last updated: 2026-09-23
State: Published
Assigner (CNA): GitHub_M

Exploit prediction (EPSS)

0.37%

Probability of exploitation in 30 days

31.4%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: No
Exploitation: None
Technical impact: Partial

Weaknesses (CWE)

CWE-918
Server-Side Request Forgery (SSRF)