Quick answers
- Is CVE-2026-38638 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-38638 being exploited in the wild.
- How severe is CVE-2026-38638?
- High severity, with a CVSS score of 7.5, published 28 August 2026.
- Which products and versions are affected?
- Redox OS Relibc commit 61f42d and earlier.
- Is there a fix for CVE-2026-38638?
- A patch was published on 2026: Fix available in merge request 989 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-38638 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-38638?
- Check whether you run Redox OS Relibc at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
An index out of bounds vulnerability exists in the with_argv function (src/header/unistd/mod.rs) when handling execl() calls with many arguments. The vulnerable code writes to out[argc] without verifying that argc fits within the allocated buffer bounds. The attack is local: an attacker executes a program that calls execl() with over 100 arguments, triggering a buffer overflow that causes an invalid opcode fault and kernel panic. A fix is available in merge request 989 at the relibc repository.
Affected products
- Redox OS relibc commit 61f42d and earlier
Timeline
- 2026-08-28: disclosed
- 2026: patched: Fix available in merge request 989