Package vulnerability, severity high

pypdf has possible large memory usage when parsing cross-reference streams

Published October 30, 2026, updated October 31, 2026

pypdf has possible large memory usage when parsing cross-reference streams. Source: GHSA-x3rh-gjgm-fmqc (CVE-2026-119209).

What's affected

• pypdf (pypi)<6.21.3

What to do

1. Upgrade pypdf to 6.21.3 or later.

Check whether you were affected

Pharon tells teams automatically when this affects something they run. To check a machine, run this in Claude Code with the Pharon plugin, in the repository that uses it:

/pharon:check-incident ghsa-x3rh-gjgm-fmqc

References

• https://osv.dev/vulnerability/GHSA-x3rh-gjgm-fmqc
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-x3rh-gjgm-fmqc
• https://nvd.nist.gov/vuln/detail/CVE-2026-119209
• https://github.com/py-pdf/pypdf/pull/4269
• https://github.com/py-pdf/pypdf/commit/a93fe3a901fd00af38f0a105c3ba7175fa72dcb4
• https://github.com/py-pdf/pypdf
• https://github.com/py-pdf/pypdf/releases/tag/6.21.3

Notice ghsa-x3rh-gjgm-fmqc, signed with key feed-prod-2026-10 (Ed25519). The Pharon CLI verifies the signature before using a notice.