--- id: CVE-2026-26740 title: >- 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. summary: >- 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. severity: high cvss: 8.2 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H' cwe: - CWE-787 vendor: giflib_project product: giflib affected: - giflib = 5.2.2 published: '2026-03-18' updated: '2026-06-30' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-26740' references: - url: >- https://github.com/zakkanijia/POC/blob/main/giflib/giftool/giflib_giftool_gce_len_heap_oobwrite_disclosure.md label: cve@mitre.org - url: 'https://access.redhat.com/errata/RHSA-2026:33452' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:33455' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:33456' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/security/cve/CVE-2026-26740' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2448747' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26740.json label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://www.cve.org/CVERecord?id=CVE-2026-26740' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-26740' - url: 'https://access.redhat.com/errata/RHSA-2026:33447' - url: 'https://access.redhat.com/errata/RHSA-2026:9689' - url: 'https://access.redhat.com/errata/RHSA-2026:9693' - url: 'https://access.redhat.com/errata/RHSA-2026:33502' - url: 'https://access.redhat.com/errata/RHSA-2026:33503' - url: 'https://access.redhat.com/errata/RHSA-2026:9683' - url: 'https://access.redhat.com/errata/RHSA-2026:9686' - url: 'https://access.redhat.com/errata/RHSA-2026:33450' - url: 'https://access.redhat.com/errata/RHSA-2026:33509' - url: 'https://access.redhat.com/errata/RHSA-2026:33451' - url: 'https://access.redhat.com/errata/RHSA-2026:33501' - url: 'https://access.redhat.com/errata/RHSA-2026:36004' - url: 'https://access.redhat.com/errata/RHSA-2026:36005' - url: 'https://access.redhat.com/errata/RHSA-2026:36006' tags: - nvd - csaf - vex - red-hat epss: 0.01029 epssPercentile: 0.62139 ingestedAt: '2026-07-01T03:50:34.535Z' patched: - enterprise_linux_appstream_eus_v_10_0 - enterprise_linux_appstream_v_10 - enterprise_linux_appstream_v_8 - enterprise_linux_appstream_aus_v_8_2 - enterprise_linux_appstream_aus_v_8_4 - enterprise_linux_appstream_eus_extension_v_8_4 - enterprise_linux_appstream_aus_v_8_6 - enterprise_linux_appstream_e4s_v_8_6 - enterprise_linux_appstream_eus_extension_v_8_6 - enterprise_linux_appstream_tus_v_8_6 - enterprise_linux_appstream_e4s_v_8_8 - enterprise_linux_appstream_tus_v_8_8 - enterprise_linux_appstream_e4s_v_9_0 - enterprise_linux_appstream_e4s_v_9_2 - enterprise_linux_appstream_e4s_v_9_4 - enterprise_linux_appstream_eus_v_9_4 - enterprise_linux_appstream_eus_v_9_6 - enterprise_linux_appstream_v_9 - enterprise_linux_codeready_linux_builder_eus_v_10_0 - enterprise_linux_codeready_linux_builder_v_10 - enterprise_linux_crb_v_8 - codeready_linux_builder_eus_v_9_4 - codeready_linux_builder_eus_v_9_6 - enterprise_linux_codeready_linux_builder_v_9 - ai_inference_server 3.2 scores: nvd: 8.2 vendor: 7.5 --- ## Overview 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. ## Affected - `giflib = 5.2.2` ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Vendor advisories - **RHSA-2026:33447** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) · released 2026-06-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:33447) - **RHSA-2026:9689** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux AppStream EUS (v.9.4), Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux AppStream (v. 9), … · released 2026-04-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:9689) - **RHSA-2026:9693** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) · released 2026-04-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:9693) - **RHSA-2026:33502** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-06-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:33502) - **RHSA-2026:33503** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-06-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:33503) - **RHSA-2026:9683** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux AppStream AUS (v. 8.2), Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4), Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream E4S (v.8.6), … · released 2026-04-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:9683) - **RHSA-2026:9686** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4), Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream E4S (v.8.6), Red Hat Enterprise Linux AppStream TUS (v.8.6), … · released 2026-04-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:9686) - **RHSA-2026:33450** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) · released 2026-06-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:33450) - **RHSA-2026:33455** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) · released 2026-06-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:33455) - **RHSA-2026:33456** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · released 2026-06-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:33456) - **RHSA-2026:33509** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-06-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:33509) - **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 6 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26740.json)