CVE-2026-107891: musl · Integer Overflow or Wraparound
Affects muslSource CVE Database V5
Not known to be exploited · CVSS 8.1 High : upgrade to 1.2.7 soon.
Data as of 5 Nov 2026, 15:47 UTC
Thin evidence
One scorer or none| CNA (mitre) | CVSS 3.1 | 8.1 |
|---|
- Patch
- Available – fixed in 1.2.7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 5 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade musl to 1.2.7.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| musl -libcmusl | Affected
| Fixed in
|
AI-suggested
Upgrade musl libc to version 1.2.7 or later, where this vulnerability has been fixed. No other mitigation or workaround is indicated by the vendor advisory.
Description
CVE-2026-107891 is an integer overflow vulnerability in musl libc versions from 0.5.0 up to but not including 1.2.7. The flaw occurs when an untrusted regular expression is processed with regcomp, potentially causing incorrect memory allocation sizes and out-of-bounds heap writes. This vulnerability has a high severity rating with a CVSS score of 8.1. It was fixed in musl libc version 1.2.7.