{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-61626", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-07-10T17:38:57.110Z", "datePublished": "2026-10-30T14:52:21.006Z", "dateUpdated": "2026-11-04T22:45:05.471Z"}, "containers": {"cna": {"title": "libass: Out-of-bounds bit clears for negative Matroska ReadOrder values", "problemTypes": [{"descriptions": [{"cweId": "CWE-787", "lang": "en", "description": "CWE-787: Out-of-bounds Write", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "LOCAL", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 7.3, "baseSeverity": "HIGH", "vectorString": "CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N", "version": "4.0"}}], "references": [{"name": "https://github.com/libass/libass/security/advisories/GHSA-5gf7-wjfm-vmvm", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/libass/libass/security/advisories/GHSA-5gf7-wjfm-vmvm"}, {"name": "https://github.com/libass/libass/commit/23da65a130bb8c5b2cf0c7df0dd7d424607f98f1", "tags": ["x_refsource_MISC"], "url": "https://github.com/libass/libass/commit/23da65a130bb8c5b2cf0c7df0dd7d424607f98f1"}, {"name": "https://github.com/libass/libass/releases/tag/0.17.5", "tags": ["x_refsource_MISC"], "url": "https://github.com/libass/libass/releases/tag/0.17.5"}], "affected": [{"vendor": "libass", "product": "libass", "versions": [{"version": ">= 0.17.4, < 0.17.5", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-30T14:52:21.006Z"}, "descriptions": [{"lang": "en", "value": "libass is a portable subtitle renderer for the ASS/SSA (Advanced Substation Alpha/Substation Alpha) subtitle format. From 0.17.4 until 0.17.5, libass event pruning does not guard negative Matroska `ReadOrder` values, allowing an attacker to clear arbitrarily many bits to zero at attacker-controlled positions near the NULL pointer. Exploitation requires a malicious Matroska stream loaded through `ass_process_chunk`, enabled read-order checking, and later pruning of the malicious events. Read-order checking is enabled by default unless `ass_set_check_readorder` is called with zero; pruning must occur explicitly through `ass_prune_events` or through automatic pruning previously enabled with `ass_configure_prune`. On common systems with arithmetic right shift, 32-bit int values, the upper address region reserved to the kernel, and matching binary/kernel architecture, the expected consequence is denial of service. More extensive exploitation on uncommon systems is theoretical and strongly constrained by the target addresses, bit-clearing-only mutation, and ASLR. This issue is fixed in version 0.17.5."}], "source": {"advisory": "GHSA-5gf7-wjfm-vmvm", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-11-04T22:44:29.050965Z", "id": "CVE-2026-61626", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-11-04T22:45:05.471Z"}}]}}

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