Quick answers
- Is CVE-2026-88839 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-88839 being exploited in the wild.
- How severe is CVE-2026-88839?
- Medium severity, with a CVSS score of 6.7, published 23 September 2026.
- Which products and versions are affected?
- Busybox before 1.37.0-9.1.
- Is there a fix for CVE-2026-88839?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- Am I affected by CVE-2026-88839?
- Check whether you run Busybox 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
The vulnerability exists in BusyBox's tokenize() function used for parsing passwd/group files, where a pointer to the end of a string is not updated after trimming operations, resulting in an out-of-bounds write. The flaw allows writing of heap pointers outside allocated bounds. This is a memory corruption vulnerability that could be triggered through crafted passwd or group file content.
Affected products
- BusyBox BusyBox before 1.37.0-9.1
Timeline
- 2026-09-23: disclosed
- 2026-09-25: advisory: Red Hat security advisory RHSA-2026:72111 issued