CVE-2026-26740

Exp

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.

Published: 2026-03-18 Last update: 2026-07-01 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-26740 is rated High Exploit Risk (63.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.62%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-26740

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-26740

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-02 0.47% 0.62% +0.15%
2 2026-06-30 0.32% 0.47% +0.15%
3 2026-06-15 — 0.32% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-26740

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 4.2 134c704f-9b21-4f2e-91b3-4a467353bcc0
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Weakness enumeration for CVE-2026-26740

GitHub Security Advisory for CVE-2026-26740

GHSA-g43h-fmhp-fvff · Severity: high — Buffer Overflow vulnerability in giflib v.5.2.2 allows a remote attacker to cause a denial of...

OS Trackers for CVE-2026-26740

vendor priority summary link
alpine — CVE-2026-26740: 1 source package rows (giflib); 9 state rows across 6 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, 3.23-main, edge-main); fixed 0, open 9. https://security.alpinelinux.org/vuln/CVE-2026-26740
debian not yet assigned CVE-2026-26740 not yet assigned priority: Debian including 1 source packages (giflib), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2026-26740
redhat high — https://access.redhat.com/security/cve/CVE-2026-26740
suse high — https://www.suse.com/security/cve/CVE-2026-26740/
ubuntu medium CVE-2026-26740 medium priority: Ubuntu including 1 source packages (giflib), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): needs-triage 7. https://ubuntu.com/security/CVE-2026-26740

Affected software / configurations for CVE-2026-26740

Vendor Product Version Raw CPE
giflib_project giflib 5.2.2 cpe:2.3:a:giflib_project:giflib:5.2.2:*:*:*:*:*:*:*

References for CVE-2026-26740

URL Tags
https://github.com/zakkanijia/POC/blob/main/giflib/giftool/giflib_giftool_gce_len_heap_oobwrite_disclosure.md Exploit Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:33447
https://access.redhat.com/errata/RHSA-2026:33450
https://access.redhat.com/errata/RHSA-2026:33451
https://access.redhat.com/errata/RHSA-2026:33452
https://access.redhat.com/errata/RHSA-2026:33455
https://access.redhat.com/errata/RHSA-2026:33456
https://access.redhat.com/errata/RHSA-2026:33501
https://access.redhat.com/errata/RHSA-2026:33502
https://access.redhat.com/errata/RHSA-2026:33503
https://access.redhat.com/errata/RHSA-2026:33509
https://access.redhat.com/security/cve/CVE-2026-26740
https://bugzilla.redhat.com/show_bug.cgi?id=2448747
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26740.json
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