---
id: CVE-2026-107891
title: >-
  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.
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.
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-190
vendor: musl -libc
product: musl
affected:
  - musl >= 0.5.0 < 1.2.7
published: '2026-11-05'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T16:09:17.753Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-107891'
references:
  - url: 'https://musl.libc.org'
  - url: 'https://www.openwall.com/lists/musl/2026/10/21/1'
  - url: >-
      https://git.musl-libc.org/cgit/musl/commit/?id=7813e9119eb5fe681b6750b8a033a0490bca0941
tags:
  - cve.org
ingestedAt: '2026-11-05T22:38:31.332Z'
---

## Overview

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.

## Affected

- `musl >= 0.5.0 < 1.2.7`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.