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Vulnerability · Published Oct 23, 2026 · Assigned by GitHub_M

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

High 7.1

In plain English

A high-severity uncontrolled resource consumption in pypdf from py-pdf. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)7.1High
Exploit odds (30 days)0.4%top 64.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12pypdfno fix listedDEBIAN-CVE-2026-115585
Debian:13pypdfno fix listedDEBIAN-CVE-2026-115585
Debian:14pypdf6.21.4-1DEBIAN-CVE-2026-115585
Debian:12pypdf2no fix listedDEBIAN-CVE-2026-115585
PyPIpypdf6.21.2GHSA-jr96-gvgh-j3r4
Ubuntu:24.04:LTSpypdfno fix listedUBUNTU-CVE-2026-115585
Ubuntu:26.04:LTSpypdfno fix listedUBUNTU-CVE-2026-115585
Ubuntu:26.10pypdfno fix listedUBUNTU-CVE-2026-115585

Affected products (as reported)

VendorProductVersions
py-pdf pypdf < 6.21.2

Weakness: CWE-400, CWE-407 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References