Is CVE-2026-38639 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-38639 being exploited in the wild.

How severe is CVE-2026-38639?

Informational severity, published 26 June 2026.

Which products and versions are affected?

Redox OS Relibc commit ab6a2e73223c9ff30cbbf5069d6758afb4cf08e3.

Is there a fix for CVE-2026-38639?

A patch was published on 2026-02-10: Merge request 990 submitted to fix the issue. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-38639 attacked?

It is attacked with local access, in a software library.

Am I affected by CVE-2026-38639?

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.

CVE-2026-38639: Redox OS relibc Denial of Service in strptime via multibyte characters

CVE-2026-38639 · Severity: info · Published 2026-06-26

relibc is a standard C library used by the Redox operating system to handle core system functions like time and date processing. A flaw in how the library handles specific text characters can cause a program to crash unexpectedly when processing specially formatted dates. This could allow a local user to disrupt services or cause applications to stop working, leading to a denial of service.

Technologies: Redox OS Relibc. Vendors: Redox OS.

Quick answers

Is CVE-2026-38639 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-38639 being exploited in the wild.
How severe is CVE-2026-38639?: Informational severity, published 26 June 2026.
Which products and versions are affected?: Redox OS Relibc commit ab6a2e73223c9ff30cbbf5069d6758afb4cf08e3.
Is there a fix for CVE-2026-38639?: A patch was published on 2026-02-10: Merge request 990 submitted to fix the issue. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-38639 attacked?: It is attacked with local access, in a software library.
Am I affected by CVE-2026-38639?: 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

A vulnerability exists in relibc's implementation of strptime.rs (specifically within parse_month and parse_weekday) due to improper handling of UTF-8 character boundaries during string slicing. When the library attempts to slice a string based on the length of expected month or weekday names, it may attempt to slice in the middle of a multibyte character, triggering a Rust runtime panic. An attacker can exploit this by passing a crafted multibyte string to the strptime() function, leading to an immediate application crash (Denial of Service). The issue was identified in commit ab6a2e7 and addressed in merge request 990.

Affected products

Redox OS relibc commit ab6a2e73223c9ff30cbbf5069d6758afb4cf08e3

Timeline

2026-02-10: patched: Merge request 990 submitted to fix the issue.
2026-06-26: advisory: CVE-2026-38639 published.

References

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