CVE-2026-26740

high

Description

Buffer Overflow vulnerability in giflib v.5.2.2 allows a remote attacker to cause a denial of service via the EGifGCBToExtension overwriting an existing Graphic Control Extension block without validating its allocated size.

References

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26740.json

https://github.com/zakkanijia/POC/blob/main/giflib/giftool/giflib_giftool_gce_len_heap_oobwrite_disclosure.md

https://bugzilla.redhat.com/show_bug.cgi?id=2448747

https://access.redhat.com/security/cve/CVE-2026-26740

https://access.redhat.com/errata/RHSA-2026:36006

https://access.redhat.com/errata/RHSA-2026:36005

https://access.redhat.com/errata/RHSA-2026:36004

https://access.redhat.com/errata/RHSA-2026:33509

https://access.redhat.com/errata/RHSA-2026:33503

https://access.redhat.com/errata/RHSA-2026:33502

https://access.redhat.com/errata/RHSA-2026:33501

https://access.redhat.com/errata/RHSA-2026:33456

https://access.redhat.com/errata/RHSA-2026:33455

https://access.redhat.com/errata/RHSA-2026:33452

https://access.redhat.com/errata/RHSA-2026:33451

https://access.redhat.com/errata/RHSA-2026:33450

https://access.redhat.com/errata/RHSA-2026:33447

Details

Source: Mitre, NVD

Published: 2026-03-18

Updated: 2026-07-07

Risk Information

CVSS v2

Base Score: 9

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H