CVE-2026-76957

highpriority · track · 31EPSS 0.001 · 1 %ileDEFRUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.11% (1st) EPSS

CVSS 7.8 · high

Is it mine?

8 products

Check your exposure

Who says so?

3 sources

cert_bund · nvd · certfr

EPSS · scored 2026-10-27

libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after-free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.

cvss

Technical severity, 0–10. One row per scoring source.

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.9–7.8

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9

v3.14.9mediumCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:Lsecondary · cve@mitre.org USexploitability 1.4 · impact 3.4

v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-416US

affected products (8)

Products and version ranges known to be affected.

Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
IBM AIX 7.3all versionscert_bundDEcpe:/o:ibm:aix:7.3
IBM VIOS 4.1all versionscert_bundDEcpe:/a:ibm:vios:4.1
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Open Source expat< 2.8.4cert_bundDE
libexpat project libexpat< 2.8.4nvdUScpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*

advisories (3)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-2930expat: Schwachstelle ermöglicht nicht spezifizierten AngriffDeutsch2026-08-19csaf · cert_bundDE
Ein lokaler Angreifer kann eine Schwachstelle in expat ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.
CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
CERTFR-2026-AVI-1390Multiples vulnérabilités dans Tenable Network MonitorFrançais2026-10-27vendor · certfrFR

sources

Which sources assert this record, and when.

cert_bund nvd certfr NVD CVE.org MITRE

published 2026-08-20modified 2026-09-03

references (2) nvd

External citations — patches, advisories, analysis.

scry

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