CVE-2026-102994 py-pdf CVE debrief

Who should care

Defenders responsible for systems using the pypdf library should assess exposure and prioritize updating to version 6.18.0 or later. This includes operators, platform administrators, vulnerability management teams, and security teams who need to review and update affected systems to prevent potential denial-of-service attacks. Defenders should also monitor for potential attacks and review compensating controls for exposed systems.

Why it matters

Defenders should prioritize updating to version 6.18.0 or later to prevent potential denial-of-service attacks. The vulnerability can cause long runtimes and application unavailability when processing crafted PDFs.

• Potential denial-of-service attacks
• Long runtimes and application unavailability

Technical summary

The pypdf library is vulnerable to a denial-of-service attack when processing crafted PDFs containing indirect-object identifiers or generation-number tokens that continue for a long time without whitespace. This vulnerability can cause long runtimes and application unavailability. The issue is fixed in version 6.18.0, and defenders should prioritize updating to this version or later to prevent potential attacks. The vulnerability affects systems using the pypdf library, emphasizing the need for defenders to assess exposure and update affected systems.

Defensive priority

Defenders should prioritize updating to version 6.18.0 or later to prevent potential denial-of-service attacks.

Recommended defensive actions

• Update to version 6.18.0 or later
• Review and update affected systems
• Monitor for potential denial-of-service attacks
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The vulnerability is caused by a crafted PDF containing indirect-object identifiers or generation-number tokens that continue for a long time without whitespace, resulting in excessive input scanning.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.