CVE-2026-41168

pypdf has possible long runtimes for wrong size values in cross-reference and object streams

MEDIUM
5.3
CVSS Score
Published: April 22, 2026 at 08:49 PM UTC
Updated: June 17, 2026 at 10:46 AM UTC
2 products affected across 2 vendorsPypdfPypdf

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.1 can craft a PDF which leads to long runtimes. This requires cross-reference streams with wrong large `/Size` values or object streams with wrong large `/N` values. This has been fixed in pypdf 6.10.1. As a workaround, one may apply the changes from the patch manually.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 6.10.1
Affected range stops below 6.10.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

x_refsource_CONFIRMMitigationPatchVendor Advisory
Source: cverecord
https://github.com/py-pdf/pypdf/security/advisories/GHSA-jj6c-8h6c-hppx
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/py-pdf/pypdf/pull/3733
x_refsource_MISCProductRelease Notes
Source: cverecord
https://github.com/py-pdf/pypdf/releases/tag/6.10.1

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-834

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