Bug 2563680 (CVE-2026-119209)

Summary: CVE-2026-119209 pypdf: pypdf: Denial of Service via crafted 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
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Hardware: All   
OS: Linux   
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A flaw was found in pypdf. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by convincing an application or user to open a specially crafted PDF document. When processed, malicious cross-reference streams force the library to allocate excessive amounts of memory, potentially crashing the application or exhausting system resources.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On: 2567267, 2567268, 2567269    
Bug Blocks:    

Description OSIDB Bzimport 2026-10-29 20:56:53 UTC
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.3, pypdf can consume excessive memory while opening a crafted PDF containing cross-reference streams that declare very large entry counts. Highly compressible streams and /Prev chains can multiply the number of parsed entries across a document, while negative /Index counts can bypass the existing per-stream clamp. This issue is fixed in version 6.21.3.