Quick answers
- Is CVE-2026-38753 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-38753 being exploited in the wild.
- How severe is CVE-2026-38753?
- Informational severity, published 15 July 2026.
- Which products and versions are affected?
- Busybox 1.38.0.
- Is there a fix for CVE-2026-38753?
- A patch was published on 2026-06-16: Patch submitted to BusyBox mailing list by Sanghyun Park Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-38753 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-38753?
- 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
A use-after-free (UAF) vulnerability exists in the awk_sub() function within editors/awk.c of BusyBox v1.38.0. The function receives a pointer to replacement text stored in AWK variable storage; however, evaluating the regular expression argument via as_regex() can trigger a reallocation or change in that storage, leaving the replacement pointer dangling. Subsequent calls to strlen() or the replacement loop then access this freed memory. An attacker who can provide a crafted AWK script to be executed by the vulnerable BusyBox binary can trigger a crash (Denial of Service). A patch has been proposed to copy the replacement string into stable storage before the regex evaluation occurs.
Affected products
- BusyBox BusyBox 1.38.0
Timeline
- 2026-06-16: patched: Patch submitted to BusyBox mailing list by Sanghyun Park
- 2026-07-15: disclosed: CVE published to NVD