Public proof of concept

CVE-2026-26740

A public proof of concept exists; no exploitation attested.

Published2026-03-18
WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC

2026-03-1818:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-26740?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-26740?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Giflib project giflib

Branch	Affected	Fixed in	Source
5.2	= 5.2.2	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

giflibAlmaLinux:10all versions · fixed in 5.2.1-25.el10_2and 1 other package
giflibAlmaLinux:9all versions · fixed in 5.2.1-10.el9_8.2and 1 other package
giflibAlmaLinux:8all versions · fixed in 5.1.4-5.el8_10and 1 other package
java-25-openjdkAlmaLinux:10all versions · fixed in 1:25.0.3.0.9-1.el10_2and 25 other packages
java-25-openjdkAlmaLinux:9all versions · fixed in 1:25.0.3.0.9-1.el9.alma.1and 25 other packages

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionpoc2026-03-18
OpenCVESSVC decisionpoc—
CISA-ADPCVSS 3.18.22026-03-18
CNACVSS 3.17.5read 2026-10-23
CISA-ADPweakness (CWE)CWE-7872026-03-18
CNAweakness (CWE)CWE-787read 2026-10-23
FIRST EPSSEPSS score1.1 %2026-10-22
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2026-03-18
Last Modified: 2026-07-23
NVD status: Modified

Frequently asked questions

What is CVE-2026-26740?

Is CVE-2026-26740 actively exploited?

A proof-of-concept exploit exists for CVE-2026-26740, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-26740?

CVE-2026-26740 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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