How severe is CVE-2026-27735?

No CVSS score has been assigned to CVE-2026-27735 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-27735?

CVE-2026-27735 affects the following packages: mcp-server-git (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-27735?

Update mcp-server-git to 2026.1.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27735 is resolved across your whole dependency graph.

How do I detect CVE-2026-27735 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mcp-server-git. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-27735 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-27735?

O3 pinpoints whether CVE-2026-27735 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-27735 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-27735 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-27735?

CVE-2026-27735 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 20th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-27735?

CVE-2026-27735 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-27735 published, and has it been updated?

CVE-2026-27735 was published on February 25, 2026 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

CVE-2026-27735

mcp-server-git : Path traversal in git_add allows staging files outside repository boundaries

Also known asGHSA-vjqx-cfc4-9h6v

Published

Feb 25, 2026

Updated

Apr 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk20th percentile+0.25%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐍mcp-server-git

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Model Context Protocol Servers is a collection of reference implementations for the model context protocol (MCP). In mcp-server-git versions prior to 2026.1.14, the git_add tool did not validate that file paths provided in the files argument were within the repository boundaries. Because the tool used GitPython's repo.index.add() rather than the Git CLI, relative paths containing ../ sequences that resolve outside the repository were accepted and staged into the Git index. Users are advised to upgrade to 2026.1.14 or newer to remediate this issue.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`mcp-server-git`	all versions	2026.1.14

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mcp-server-git. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update mcp-server-git to 2026.1.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27735 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-27735 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-27735. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Model Context Protocol Servers is a collection of reference implementations for the model context protocol (MCP). In mcp-server-git versions prior to 2026.1.14, the git_add tool did not validate that file paths provided in the files argument were within the repository boundaries. Because the tool used GitPython's repo.index.add() rather than the Git CLI, relative paths containing `../` sequences that resolve outside the repository were accepted and staged into the Git index. Users are advised to upgrade to 2026.1.14 or newer to remediate this issue.

O3 Security · Impact-Aware SCA

Is CVE-2026-27735 in your dependencies?

O3 detects CVE-2026-27735 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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