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Fencer Intel
high 8.1

CVE-2026-107891 json

musl libc before 1.2.7, when an untrusted regular expression is used with regcomp, has multiple integer overflows, possibly leading to inco…

published 4d ago modified 4h ago also EUVD-2026-117543

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 46%
public exploits
0
none known

Summary

musl libc before 1.2.7, when an untrusted regular expression is used with regcomp, has multiple integer overflows, possibly leading to incorrect allocation sizes and out-of-bounds heap writes.

Patch / fix

  • musl -libc musl 1.2.7
  • musl Debian 14 1.2.6-2

debian advisories DEBIAN-CVE-2026-107891

  • musl Alpine 3.20 1.2.5-r4
  • musl Alpine 3.21 1.2.5-r12
  • musl Alpine 3.22 1.2.5-r13
  • musl Alpine 3.23 1.2.5-r24
  • musl Alpine 3.24 1.2.6-r3

alpine advisories ALPINE-CVE-2026-107891

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-107891 updated cvss 8.1

musl: musl: Arbitrary code execution via integer overflow in regcomp

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
4h ago

Exploit prediction

0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • musl -libc musl

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.