{"id":"UBUNTU-CVE-2023-42821","details":"The package `github.com/gomarkdown/markdown` is a Go library for parsing Markdown text and rendering as HTML. Prior to pseudoversion `0.0.0-20230922105210-14b16010c2ee`, which corresponds with commit `14b16010c2ee7ff33a940a541d993bd043a88940`, parsing malformed markdown input with parser that uses parser.Mmark extension could result in out-of-bounds read vulnerability. To exploit the vulnerability, parser needs to have `parser.Mmark` extension set. The panic occurs inside the `citation.go` file on the line 69 when the parser tries to access the element past its length. This can result in a denial of service. Commit `14b16010c2ee7ff33a940a541d993bd043a88940`/pseudoversion `0.0.0-20230922105210-14b16010c2ee` contains a patch for this issue.","modified":"2026-05-20T16:07:43.847308174Z","published":"2023-09-22T17:15:00Z","upstream":["CVE-2023-42821"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2023-42821"},{"type":"REPORT","url":"https://github.com/gomarkdown/markdown/commit/14b16010c2ee7ff33a940a541d993bd043a88940"},{"type":"REPORT","url":"https://github.com/gomarkdown/markdown/security/advisories/GHSA-m9xq-6h2j-65r2"},{"type":"REPORT","url":"https://github.com/gomarkdown/markdown/blob/7478c230c7cd3e7328803d89abe591d0b61c41e4/parser/citation.go#L69"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2023-42821"}],"affected":[{"package":{"name":"golang-github-gomarkdown-markdown","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/golang-github-gomarkdown-markdown?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0~git20220731.dcdaee8-2","0.0~git20231115.a660076-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.0~git20231115.a660076-1","binary_name":"golang-github-gomarkdown-markdown-dev"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-42821.json"}},{"package":{"name":"golang-github-gomarkdown-markdown","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/golang-github-gomarkdown-markdown?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0~git20231115.a660076-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-gomarkdown-markdown-dev","binary_version":"0.0~git20231115.a660076-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-42821.json"}},{"package":{"name":"golang-github-gomarkdown-markdown","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/golang-github-gomarkdown-markdown?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0~git20231115.a660076-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-gomarkdown-markdown-dev","binary_version":"0.0~git20231115.a660076-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-42821.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}