{"id":"CVE-2020-5238","aliases":["ALSA-2021:1972","DEBIAN-CVE-2020-5238","EUVD-2020-26457","GHSA-7gc6-9qr5-hc85","RHSA-2021:1972","RSEC-2023-6","UBUNTU-CVE-2020-5238"],"status":"published","title":"Denial of service in table parsing in cmark-gfm","description":"The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project. 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Party Advisory","advisory","report"]},{"url":"https://github.com/github/cmark-gfm/commit/85d895289c5ab67f988ca659493a64abb5fec7b4","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","report"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TCDHBTUFIOYRIS5HAS6PZNBNMB7IOAX3/","tags":["vendor-advisory","x_refsource_FEDORA","x_transferred","web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZGJH2A4VAV54X6NSCNNGSEIGIIY5N2VR/","tags":["vendor-advisory","x_refsource_FEDORA","x_transferred","web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WMQFOQQCWOAMQ4I2XIVCVOXXIJ75HDCW/","tags":["vendor-advisory","x_refsource_FEDORA","x_transferred","web"]},{"url":"https://errata.almalinux.org/8/ALSA-2021-1972.html","tags":["advisory"]},{"url":"https://vulners.com/cve/CVE-2020-5238","tags":["report"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2020-5238","tags":["advisory","web"]},{"url":"https://access.redhat.com/errata/RHSA-2021:1972","tags":["advisory"]},{"url":"https://access.redhat.com/security/updates/classification/#moderate","tags":["article"]},{"url":"https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.4_release_notes/","tags":["article"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=1854328","tags":["report"]},{"url":"https://security.access.redhat.com/data/csaf/v2/advisories/2021/rhsa-2021_1972.json","tags":["advisory"]},{"url":"https://access.redhat.com/security/cve/CVE-2020-5238","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2020-5238","tags":["advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-5238","tags":["advisory"]},{"url":"https://github.com/r-lib/commonmark/issues/13","tags":["web"]},{"url":"https://github.com/r-lib/commonmark/pull/18","tags":["web"]},{"url":"https://ubuntu.com/security/CVE-2020-5238","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2020-5238","title":"Denial of service in table parsing in cmark-gfm","description":"The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project. The issue has been fixed in version 0.29.0.gfm.1.","status":"published","published":"2020-07-01T23:05:15Z","modified":"2024-08-04T08:22:09.078Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:35:47.56691Z"}],"euvd":[{"id":"EUVD-2020-26457","description":"The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project. 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The issue has been fixed in version 0.29.0.gfm.1.","status":"published","published":"2020-07-01T23:15:10.443Z","modified":"2026-06-17T03:21:06.427Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":4,"vector":"AV:N/AC:L/Au:S/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:06:08.145904Z"}],"osv":[{"id":"CVE-2020-5238","description":"The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project. The issue has been fixed in version 0.29.0.gfm.1.","status":"published","published":"2020-07-01T23:15:10.443Z","modified":"2026-10-20T10:54:22.478999037Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:44:16.936975Z"},{"id":"DEBIAN-CVE-2020-5238","description":"The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project. 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The issue has been fixed in version 0.29.0.gfm.1.","status":"published","published":"2020-07-01T23:15:00Z","modified":"2026-10-17T12:56:14.009478865Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:54:25.179924Z"},{"id":"ALSA-2021:1972","title":"Moderate: pandoc security update","description":"Pandoc is a Haskell library for converting from one markup format to another, and a command-line tool that uses this library.\n\nSecurity Fix(es):\n\n* cmark-gfm: Exponential time to parse certain inputs could lead to DoS (CVE-2020-5238)\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.\n\nAdditional Changes:\n\nFor detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.","status":"published","published":"2021-05-18T06:31:29Z","modified":"2026-10-29T11:00:56.374899597Z","updated_at":"2026-11-02T15:27:51.196609Z"},{"id":"RSEC-2023-6","title":"Denial of Service (DoS) vulnerability","description":"The commonmark package, specifically in its dependency on GitHub Flavored Markdown before version 0.29.0.gfm.1, has a vulnerability related to time complexity. Parsing certain crafted markdown tables can take O(n * n) time, leading to potential Denial of Service attacks. This issue does not affect the upstream cmark project and has been fixed in version 0.29.0.gfm.1.","status":"published","published":"2023-10-06T05:00:00.6Z","modified":"2025-05-19T19:43:47.903227Z","updated_at":"2026-11-02T15:53:39.492624Z"}]}}