🛡️ CVE-2026-59937 — pypdf

🟠 CVSS 7.5 — High ✅ No Known Exploit CWE-400 OSV
7.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

pypdf: Possible long runtimes for repeated malformed cross-reference entries

Impact

An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with repeated malformed cross-reference streams.

Patches

This has been fixed in [pypdf==6.14.0](https://github.com/py-pdf/pypdf/releases/tag/6.14.0).

Workarounds

If you cannot upgrade yet, consider applying the changes from PR [#3887](https://github.com/py-pdf/pypdf/pull/3887).

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. Rated impact: confidentiality none, integrity none, availability low.

Weakness class

CVE-2026-59937 is classified as CWE-400: Uncontrolled Resource Consumption. A request can consume memory, CPU or storage without limit, exhausting capacity for everyone else.

Affected software

CVE-2026-59937 is recorded against 1 package.

  • pypdf (fixed in 6.14.0)

Timeline and source

Published on 23 July 2026 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from OSV.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Web)
github.com (Web)
github.com (Package)
github.com (Web)

Details

Severity HIGH
CVSS Score 7.5
CVSS Vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CWE CWE-400
Public Exploit ✅ No
Source OSV
Published 2026-07-23
Updated 2026-08-12
Modified 2026-08-04

Affected Packages

Software From version Fixed in
pypdf — 6.14.0

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