{"id":"CVE-2026-61627","state":"PUBLISHED","title":"libass: Out-of-bounds read and write in wrap_lines_measure","description":"libass is a portable subtitle renderer for the `ASS`/SSA (Advanced Substation Alpha/Substation Alpha) subtitle format. Prior to 0.17.5, libass can overread and overwrite the glyph array in `wrap_lines_measure` while rendering malicious `ASS` content. In `wrap modes other than two`, a final line ending with a literal backslash-n sequence and otherwise consisting only of such sequences or spaces can remain after early trimming and make the line-measurement loops overshoot by one glyph. When the total text size exactly matches the allocated glyph-array capacity, the first loop reads an uninitialized 32-bit fixed-point `pos.x` value, although that value is not subsequently used. The second loop writes `pos.x` and `pos.y` beyond the array, zeroing the first and adding an attacker-controllable offset to the second. No actual exploitation beyond possible denial of service is known; broader exploitation is theoretical and constrained by the addresses, limited writes, and ASLR. This issue is fixed in version 0.17.5.","publishedAt":"2026-10-30T14:55:45.500Z","updatedAt":"2026-10-30T15:51:10.521Z","severity":{"score":7.3,"label":"High","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["libass libass"],"affected":[{"vendor":"libass","product":"libass","versions":[{"version":"< 0.17.5","status":"affected"}]}],"references":["https://github.com/libass/libass/security/advisories/GHSA-pjjp-65r7-ppgm","https://github.com/libass/libass/commit/f2ef59755292bc4bb950ef22710e18a5487c399d","https://github.com/libass/libass/releases/tag/0.17.5","https://lists.debian.org/debian-lts-announce/2026/09/msg00004.html"],"weaknesses":["CWE-125","CWE-787"],"ingestedAt":"2026-10-30T15:58:06.618Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/61xxx/CVE-2026-61627.json","commit":"2b1b837cd89354d9c9a57d56e0640dc825b19235","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-61627","state":"PUBLISHED","datePublished":"2026-10-30T14:55:45.500Z","dateUpdated":"2026-10-30T15:51:10.521Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-10T17:38:57.110Z"},"containers":{"cna":{"title":"libass: Out-of-bounds read and write in wrap_lines_measure","descriptions":[{"lang":"en","value":"libass is a portable subtitle renderer for the `ASS`/SSA (Advanced Substation Alpha/Substation Alpha) subtitle format. Prior to 0.17.5, libass can overread and overwrite the glyph array in `wrap_lines_measure` while rendering malicious `ASS` content. In `wrap modes other than two`, a final line ending with a literal backslash-n sequence and otherwise consisting only of such sequences or spaces can remain after early trimming and make the line-measurement loops overshoot by one glyph. When the total text size exactly matches the allocated glyph-array capacity, the first loop reads an uninitialized 32-bit fixed-point `pos.x` value, although that value is not subsequently used. The second loop writes `pos.x` and `pos.y` beyond the array, zeroing the first and adding an attacker-controllable offset to the second. No actual exploitation beyond possible denial of service is known; broader exploitation is theoretical and constrained by the addresses, limited writes, and ASLR. This issue is fixed in version 0.17.5."}],"affected":[{"vendor":"libass","product":"libass","versions":[{"version":"< 0.17.5","status":"affected"}]}],"references":[{"url":"https://github.com/libass/libass/security/advisories/GHSA-pjjp-65r7-ppgm","name":"https://github.com/libass/libass/security/advisories/GHSA-pjjp-65r7-ppgm","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/libass/libass/commit/f2ef59755292bc4bb950ef22710e18a5487c399d","name":"https://github.com/libass/libass/commit/f2ef59755292bc4bb950ef22710e18a5487c399d","tags":["x_refsource_MISC"]},{"url":"https://github.com/libass/libass/releases/tag/0.17.5","name":"https://github.com/libass/libass/releases/tag/0.17.5","tags":["x_refsource_MISC"]}],"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","description":"CWE-125: Out-of-bounds Read","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-787","lang":"en","description":"CWE-787: Out-of-bounds Write","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-30T14:55:45.500Z"},"source":{"advisory":"GHSA-pjjp-65r7-ppgm","discovery":"UNKNOWN"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2026/09/msg00004.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-10-30T15:10:45.937Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-30T15:34:57.627086Z","id":"CVE-2026-61627","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-30T15:51:10.521Z"}}]}}}