{"id":"JLSEC-2026-1373","details":"libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, libgit2 performs a fixed-size strncmp in `set_data` in `src/libgit2/transports/smart_pkt.c` without first verifying that the smart-protocol pkt-line capability buffer contains 14 bytes. A malicious Git server can make bytes after the pkt-line complete object-format=, causing `format_str` to advance beyond the pkt-line and the following memchr length calculation to underflow. The resulting heap out-of-bounds walk can crash a client during the first refs-advertisement packet over HTTP, HTTPS, SSH, or the Git protocol. This issue is fixed in versions 1.8.6 and 1.9.5.","modified":"2026-08-21T21:30:03.330665751Z","published":"2026-08-21T21:14:18.508Z","upstream":["CVE-2026-53587","EUVD-2026-63547"],"database_specific":{"sources":[{"html_url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53587","database_specific":{"status":"Received"},"id":"CVE-2026-53587","imported":"2026-08-21T20:45:03.782Z","modified":"2026-08-20T20:17:34.557Z","published":"2026-08-20T19:16:55.137Z","url":"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-53587"},{"affected":{"libgit2:libgit2":["1.9.0, \u003c 1.9.5","\u003c 1.8.6"]},"id":"EUVD-2026-63547","imported":"2026-08-21T20:45:01.752Z","modified":"2026-08-20T19:18:33Z","published":"2026-08-20T18:36:43Z","url":"https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2026-63547","html_url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-63547"}],"license":"CC-BY-4.0"},"references":[{"type":"WEB","url":"https://github.com/libgit2/libgit2/commit/2c0ce8c0132ac38ab0db28239462a671e2e5440e"},{"type":"WEB","url":"https://github.com/libgit2/libgit2/commit/affda60c10fcef16723451c0d7dc71b71dc20ad3"},{"type":"WEB","url":"https://github.com/libgit2/libgit2/commit/d7a9fb87f504434e9f45228678953c4fa56e7640"},{"type":"WEB","url":"https://github.com/libgit2/libgit2/releases/tag/v1.8.6"},{"type":"WEB","url":"https://github.com/libgit2/libgit2/releases/tag/v1.9.5"},{"type":"WEB","url":"https://github.com/libgit2/libgit2/security/advisories/GHSA-pm24-4jhq-3xvm"}],"affected":[{"package":{"name":"LibGit2_jll","ecosystem":"Julia","purl":"pkg:julia/LibGit2_jll?uuid=e37daf67-58a4-590a-8e99-b0245dd2ffc5"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.9.6+0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1373.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"CNA"}]}