{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-33018", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-03-17T17:22:14.666Z", "datePublished": "2026-04-14T21:45:42.261Z", "dateUpdated": "2026-04-14T21:45:42.261Z"}, "containers": {"cna": {"title": "libsixel: Use-After-Free in load_gif()", "problemTypes": [{"descriptions": [{"cweId": "CWE-416", "lang": "en", "description": "CWE-416: Use After Free", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/saitoha/libsixel/security/advisories/GHSA-w46f-jr9f-rgvp", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/saitoha/libsixel/security/advisories/GHSA-w46f-jr9f-rgvp"}, {"name": "https://github.com/saitoha/libsixel/releases/tag/v1.8.7-r1", "tags": ["x_refsource_MISC"], "url": "https://github.com/saitoha/libsixel/releases/tag/v1.8.7-r1"}], "affected": [{"vendor": "saitoha", "product": "libsixel", "versions": [{"version": "< 1.8.7-rc1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-04-14T21:45:42.261Z"}, "descriptions": [{"lang": "en", "value": "libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a Use-After-Free vulnerability via the load_gif() function in fromgif.c, where a single sixel_frame_t object is reused across all frames of an animated GIF and gif_init_frame() unconditionally frees and reallocates frame->pixels between frames without consulting the object's reference count. Because the public API explicitly provides sixel_frame_ref() to retain a frame and sixel_frame_get_pixels() to access the raw pixel buffer, a callback following this documented usage pattern will hold a dangling pointer after the second frame is decoded, resulting in a heap use-after-free confirmed by ASAN. Any application using sixel_helper_load_image_file() with a multi-frame callback to process user-supplied animated GIFs is affected, with a reliable crash as the minimum impact and potential for code execution. This issue has been fixed in version 1.8.7-r1."}], "source": {"advisory": "GHSA-w46f-jr9f-rgvp", "discovery": "UNKNOWN"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a Use-After-Free vulnerability via the load_gif() function in fromgif.c, where a single sixel_frame_t object is reused across all frames of an animated GIF and gif_init_frame() unconditionally frees and reallocates frame->pixels between frames without consulting the object's reference count. Because the public API explicitly provides sixel_frame_ref() to retain a frame and sixel_frame_get_pixels() to access the raw pixel buffer, a callback following this documented usage pattern will hold a dangling pointer after the second frame is decoded, resulting in a heap use-after-free confirmed by ASAN. Any application using sixel_helper_load_image_file() with a multi-frame callback to process user-supplied animated GIFs is affected, with a reliable crash as the minimum impact and potential for code execution. This issue has been fixed in version 1.8.7-r1."}], "id": "CVE-2026-33018", "lastModified": "2026-04-14T22:16:30.213", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.0, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.0, "impactScore": 5.9, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-04-14T22:16:30.213", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/saitoha/libsixel/releases/tag/v1.8.7-r1"}, {"source": "security-advisories@github.com", "url": "https://github.com/saitoha/libsixel/security/advisories/GHSA-w46f-jr9f-rgvp"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}