CVE-2026-102998: pypdf: Possible long runtimes when generating appearance streams

October 1, 2026

An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires updating form field values with flattening enabled, which triggers appearance stream generation.

References

github.com/advisories/GHSA-php9-fj8v-98fj
github.com/py-pdf/pypdf/commit/959467a9b95be83e2dc5ae873ece5f371263ede7
github.com/py-pdf/pypdf/pull/4087
github.com/py-pdf/pypdf/releases/tag/6.19.0
github.com/py-pdf/pypdf/security/advisories/GHSA-php9-fj8v-98fj
nvd.nist.gov/vuln/detail/CVE-2026-102998

Code Behaviors & Features

Detect and mitigate CVE-2026-102998 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →