What’s Vulnerable › Vulnerabilities

CVE-2026-115585: pypdf: Possible long runtimes for repeated malformed cross-reference entries (Follow-up)

• Severity: high (CVSS 7.1 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-23 · updated 2026-10-30
• Weakness: CWE-400

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.2, an incomplete remediation for repeated malformed cross-reference entries in GHSA-55h5-xmcq-c37v could still trigger a complete PDF stream reload during each recovery attempt even when a recovery cache was present, causing crafted cross-reference streams to produce long runtimes. This issue is fixed in version 6.21.2.

Affected products

• py-pdf pypdf: before 6.21.2

References

• https://github.com/py-pdf/pypdf/commit/68a0e5046cc9e14a6c24a21a713f3c7fbde18b4b
• https://github.com/py-pdf/pypdf/pull/4240
• https://github.com/py-pdf/pypdf/releases/tag/6.21.2
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-jr96-gvgh-j3r4

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