{"id":"CVE-2026-28804","aliases":["GHSA-9m86-7pmv-2852","PYSEC-2026-3014"],"title":"pypdf vulnerable to inefficient decoding of ASCIIHexDecode streams","summary":"pypdf vulnerable to inefficient decoding of ASCIIHexDecode streams","severity":"medium","vendor":"pypdf","product":"pypdf","ecosystem":"pip","affected":["pypdf < 6.7.5"],"patched":["pypdf 6.7.5"],"published":"2026-03-02","updated":"2026-09-10","sourceUpdated":"2026-09-10T03:50:38.603469156Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-9m86-7pmv-2852","references":[{"url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-9m86-7pmv-2852"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-28804"},{"url":"https://github.com/py-pdf/pypdf/pull/3666"},{"url":"https://github.com/py-pdf/pypdf/commit/648c627d2657447dfb1773412af05a0a5103b98f"},{"url":"https://github.com/py-pdf/pypdf"},{"url":"https://github.com/py-pdf/pypdf/releases/tag/6.7.5"}],"tags":["osv","pip"],"epss":0.00399,"epssPercentile":0.33844,"ingestedAt":"2026-07-13T18:57:56.000Z","slug":"CVE-2026-28804","body":"## Overview\n\n### Impact\nAn attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the `/ASCIIHexDecode` filter.\n\n### Patches\nThis has been fixed in [pypdf==6.7.5](https://github.com/py-pdf/pypdf/releases/tag/6.7.5).\n\n### Workarounds\nIf you cannot upgrade yet, consider applying the changes from PR [#3666](https://github.com/py-pdf/pypdf/pull/3666).\n\n## Affected packages\n\n- `pypdf < 6.7.5`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `pypdf 6.7.5`","depth":"sunlit","depthScore":28,"depthScoreParts":{"impact":27.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}