PYSEC-2026-4156
pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)
At a glance
- Published
- Updated
- CVE
- CVE-2026-102997
- Aliases
- GHSA-jw7q-gvrg-4vj3
- CVSS_V4
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Description
### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a partially malformed `/FlateDecode` stream, where the byte-by-byte decompression is used. ### 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 [#4073](https://github.com/py-pdf/pypdf/pull/4073).
Affected packages
| Package | Versions |
|---|---|
| PyPI · pypdf | introduced 0, fixed 6.18.1 |
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-jw7q-gvrg-4vj3 WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-102997 ADVISORY
- https://github.com/py-pdf/pypdf/pull/4073 WEB
- https://github.com/py-pdf/pypdf/commit/d9d38cf99b115deb562d3b68f36c33027bc04f79 WEB
- https://github.com/py-pdf/pypdf PACKAGE
- https://github.com/py-pdf/pypdf/releases/tag/6.18.1 WEB
- https://pypi.org/project/pypdf PACKAGE
- https://github.com/advisories/GHSA-jw7q-gvrg-4vj3 ADVISORY
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — PyPA Advisory Database |