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Fencer Vulns
high 8.1

CVE-2026-40200 json

An issue was discovered in musl libc 0.7.10 through 1.2.6.

published 2026-04-10 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-21496

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

An issue was discovered in musl libc 0.7.10 through 1.2.6. Stack-based memory corruption can occur during qsort of very large arrays, due to incorrectly implemented double-word primitives. The number of elements must exceed about seven million, i.e., the 32nd Leonardo number on 32-bit platforms (or the 64th Leonardo number on 64-bit platforms, which is not practical).

Patch / fix

  • musl Debian 13 1.2.5-3.1~deb13u1
  • musl Debian 14 1.2.5-3.1

debian advisories DEBIAN-CVE-2026-40200

  • musl Alpine 3.19 1.2.4_git20230717-r6
  • musl Alpine 3.20 1.2.5-r3
  • musl Alpine 3.21 1.2.5-r11
  • musl Alpine 3.22 1.2.5-r12
  • musl Alpine 3.23 1.2.5-r23
  • musl Alpine 3.24 1.2.6-r2

alpine advisories ALPINE-CVE-2026-40200

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

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-2026-40200 updated cvss 7.8

musl: musl libc: Arbitrary code execution and denial of service via stack-based memory corruption in qsort

  • 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
6 mo ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

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

Affected products

  • musl-libc musl

Classification

Weakness
  • CWE-670 Always-Incorrect Control Flow Implementation

References

Sources

Fencer Vulns 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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.