Code execution via intra-directory module overwrite
Published Sep 22, 2026 · Updated Sep 22, 2026
Path traversal in MCP Atlassian before 0.22.0 allows attackers to overwrite Python modules and execute code via attachment paths. validate_safe_path defaults its containment root to the current working directory, while affected Confluence attachment callers omit base_dir and permit attacker-selected writes there. Exploitation requires access to an affected attachment call and later import of the overwritten module by the server process.
Summary
What happened
Path traversal in MCP Atlassian before 0.22.0 allows attackers to overwrite Python modules and execute code via attachment paths. validate_safe_path defaults its containment root to the current working directory, while affected Confluence attachment callers omit base_dir and permit attacker-selected writes there. Exploitation requires access to an affected attachment call and later import of the overwritten module by the server process.
The record
- CVE
- CVE-2026-77271
- Published
- Sep 22, 2026
- Updated
- Sep 22, 2026
- Vendor
- sooperset
- Product
- MCP Atlassian
- Classifications
- T1190
- Attack vector
- network
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 22, 2026CVE publishedPublication date reported by the CVE source.
- Sep 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 0.22.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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