Vulnerability GHSA-39mj-jf6j-2qj3
Medium Risk
MEDIUM RISK
CVSS Score: 6.0
Score Range: 4.0–6.9
Medium severity vulnerabilities (CVSS 4.0–6.9). Important issues that meaningfully reduce security confidence.
1 hour ago
October 21, 2026 at 04:54 PM UTC
pypdf: Possible infinite loop when hitting EOF in standard xref table
1.0 - 6.19.0
1.0 - 6.19.0
Summary
pypdf: Possible infinite loop when hitting EOF in standard xref table
Details
Impact
An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires an incomplete file which ends inside the xref table.
Patches
This has been fixed in pypdf==6.20.0.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #4170.
Notes
This has been reported through both the secure channel and as a public issue at #4169.
Related Vulnerabilities
Other vulnerabilities affecting the same packages
Medium Risk
1 hour ago
pypdf: Possible infinite loop in PdfWriter.find_outline_item
1.0 - 6.20.0 GHSA-qfv9-64jg-mh7p
1.0 - 6.20.0 GHSA-qfv9-64jg-mh7p
Medium Risk
1 hour ago
pypdf: Possible infinite loop when removing tree items
1.0 - 6.20.0 GHSA-9mx8-4j7g-633p
1.0 - 6.20.0 GHSA-9mx8-4j7g-633p
Medium Risk
2 hours ago
pypdf: Possible large memory usage for streams with multiple filters
1.0 - 6.19.0 GHSA-7mh2-4gg2-979f
1.0 - 6.19.0 GHSA-7mh2-4gg2-979f
Unknown
20 days ago
pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)
1.0 - 6.18.0 PYSEC-2026-4156
1.0 - 6.18.0 PYSEC-2026-4156
Unknown
20 days ago
pypdf: Possible long runtimes when generating appearance streams
1.0 - 6.18.1 PYSEC-2026-4157
1.0 - 6.18.1 PYSEC-2026-4157
Impacted packages
Timeline
Published
1 hour ago
October 21, 2026 at 04:54 PM UTC
Fixed (6.20.0)
12 days ago
October 09, 2026 at 10:49 AM UTC
Last Modified
1 hour ago
October 21, 2026 at 05:00 PM UTC