pypdf: Possible large memory usage when parsing font data
### Impact An attacker who uses this vulnerability can craft a PDF which leads to large memory consumption. This requires parsing the `/Widths` entry of a TrueType or Type1 fonts with unusually large values, for example during text extraction. ### Patches This has been fixed in [pypdf==6.18.1](https://github.com/py-pdf/pypdf/releases/tag/6.18.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#4072](https://github.com/py-pdf/pypdf/pull/4072).
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-102996US | high7.5 | — | ||
pypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF can provide a TrueType or Type1 simple font with an unusually large /Widths array, causing p… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/advisories/GHSA-g9cg-prrw-2r8qADVISORY
- https://github.com/py-pdf/pypdfPACKAGE
- https://github.com/py-pdf/pypdf/commit/0fb26eb8cdd01c44b3b2c9fe8329751be2f7cfd5WEB
- https://github.com/py-pdf/pypdf/pull/4072WEB
- https://github.com/py-pdf/pypdf/releases/tag/6.18.1WEB
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-g9cg-prrw-2r8qWEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-102996ADVISORY
- https://pypi.org/project/pypdfPACKAGE
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