CVE-2026-77242: sooperset mcp-atlassian · Time-of-check Time-of-use (TOCTOU) Race Condition
Affects sooperset mcp-atlassianSource CVE Database V5
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.5 High : upgrade to 0.22.0 soon.
Data as of 5 Nov 2026, 23:24 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.22.0
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 22 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade mcp-atlassian and sooperset/mcp-atlassian to 0.22.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| soopersetmcp-atlassian | Affected
| Fixed in
|
GitHubsooperset/mcp-atlassianpkg:github/sooperset/mcp-atlassianOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade sooperset mcp-atlassian to version 0.22.0 or later, where this TOCTOU race condition vulnerability is fixed. No other mitigations are indicated or required according to the advisory.
Description
CVE-2026-77242 is a time-of-check to time-of-use (TOCTOU) race condition vulnerability in sooperset's mcp-atlassian server prior to version 0.22.0. The flaw arises because the hostname validation function validate_url_for_ssrf resolves DNS addresses separately from the actual connection attempt, allowing an attacker to exploit short-lived DNS responses to bypass SSRF protections. This can lead to unauthorized access to internal or metadata endpoints. The issue is fixed in version 0.22.0.
References
- github.com/sooperset/mcp-atlassian/security/advisories/GHSA-72fm-whvq-jghf (opens in a new tab)
- github.com/sooperset/mcp-atlassian/pull/1448 (opens in a new tab)
- github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 (opens in a new tab)
- github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 (opens in a new tab)