Bug 2560166 (CVE-2026-115585)

Summary: CVE-2026-115585 pypdf: pypdf: Denial of Service via malformed cross-reference streams
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: anpicker, bbrownin, blitton, doconnor, dschmidt, ebourniv, hasun, jfula, jlanda, jowilson, kshier, mbarnett, nyancey, ometelka, ptisnovs, rbobbitt, sbunciak, simaishi, stcannon, syedriko, xdharmai, yguenane
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in pypdf. A remote attacker could cause a Denial of Service (DoS) by convincing a user or automated system to process a crafted PDF file containing repeated malformed cross-reference entries. Due to an issue in the stream recovery caching mechanism, the library repeatedly reloads the entire PDF stream during each recovery attempt, resulting in excessive processing time and resource exhaustion.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-10-23 19:41:38 UTC
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.