How severe is GHSA-m3c4-prhw-mrx6?

GHSA-m3c4-prhw-mrx6 has a CVSS score of 8.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-m3c4-prhw-mrx6?

GHSA-m3c4-prhw-mrx6 affects the following packages: deno (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-m3c4-prhw-mrx6?

Update deno to 2.5.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m3c4-prhw-mrx6 is resolved across your whole dependency graph.

How do I detect GHSA-m3c4-prhw-mrx6 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for deno. 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 GHSA-m3c4-prhw-mrx6 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 GHSA-m3c4-prhw-mrx6?

O3 pinpoints whether GHSA-m3c4-prhw-mrx6 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 GHSA-m3c4-prhw-mrx6 actively exploited in the wild?

No public exploit code has been indexed for GHSA-m3c4-prhw-mrx6 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 GHSA-m3c4-prhw-mrx6?

GHSA-m3c4-prhw-mrx6 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 45th 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.

When was GHSA-m3c4-prhw-mrx6 published, and has it been updated?

GHSA-m3c4-prhw-mrx6 was published on January 16, 2026 and was last updated on February 3, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀 crates.io

GHSA-m3c4-prhw-mrx6

HIGH

Deno has an incomplete fix for command-injection prevention on Windows — case-insensitive extension bypass

Also known asCVE-2026-22864

Published

Jan 16, 2026

Updated

Feb 3, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk45th percentile+0.58%

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

🦀deno

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

Description

Summary

A prior patch aimed to block spawning Windows batch/shell files by returning an error when a spawned path’s extension matched .bat or .cmd. That check performs a case-sensitive comparison against lowercase literals and therefore can be bypassed when the extension uses alternate casing (for example .BAT, .Bat, etc.).

POC

const command = new Deno.Command('./test.BAT', {
  args: ['&calc.exe'],
});
const child = command.spawn();

This causes calc.exe to be launched; see the attached screenshot for evidence.

Patched in CVE-2025-61787 — prevents execution of .bat and .cmd files: photo_2025-10-10 02 27 23

Bypass of the patched vulnerability: photo_2025-10-10 02 27 25

Impact

The script launches calc.exe on Windows, demonstrating that passing user-controlled arguments to a spawned batch script can result in command-line injection.

Mitigation

Users should update to Deno v2.5.6 or newer.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`deno`	all versions	2.5.6

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for deno. 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 deno to 2.5.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m3c4-prhw-mrx6 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 GHSA-m3c4-prhw-mrx6 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 GHSA-m3c4-prhw-mrx6. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary A prior patch aimed to block spawning Windows batch/shell files by returning an error when a spawned path’s extension matched `.bat` or `.cmd`. That check performs a case-sensitive comparison against lowercase literals and therefore can be bypassed when the extension uses alternate casing (for example `.BAT, .Bat`, etc.). ### POC ```javascript const command = new Deno.Command('./test.BAT', { args: ['&calc.exe'], }); const child = command.spawn(); ``` This causes `calc.exe` to be launched; see the attached screenshot for evidence. **Patched in `CVE-2025-61787` — prevents executi

O3 Security · Impact-Aware SCA

Is GHSA-m3c4-prhw-mrx6 in your dependencies?

O3 detects GHSA-m3c4-prhw-mrx6 across crates.io 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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