CVE-2026-102998 py-pdf CVE debrief

Who should care

Defenders responsible for systems and applications using the pypdf library should assess exposure and prioritize updating to version 6.19.0 or later. The vulnerability can cause excessive runtimes and application unavailability when processing crafted PDFs with form field values and flattening enabled, emphasizing the need for defenders to review and update affected systems and applications. Defenders should also monitor for potential denial-of-service

Why it matters

Defenders should prioritize updating to version 6.19.0 or later to prevent potential denial-of-service attacks. The vulnerability can cause excessive runtimes and application unavailability when processing crafted PDFs with form field values and flattening enabled.

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

Technical summary

The pypdf library is vulnerable to a denial-of-service attack when processing crafted PDFs with form field values and flattening enabled. This can cause excessive runtimes and application unavailability. The vulnerability affects systems and applications using the pypdf library, emphasizing the need for defenders to assess exposure and prioritize updating to version 6.19.0 or later. The issue is fixed in version 6.19.0, according to the vendor's release notes. Defenders should review and update affected systems and applications to prevent potential attacks.

Defensive priority

Defenders should prioritize updating to version 6.19.0 or later to prevent potential denial-of-service attacks.

Recommended defensive actions

• Update to pypdf version 6.19.0 or later
• Review and update affected systems and applications
• 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 described in the CVE record and NVD vulnerability detail page. The issue is fixed in version 6.19.0, according to the vendor's release notes. The CVE record was published on 2026-09-30T21:17:07.177Z and has not been modified since then. The NVD vulnerability detail page provides additional information about the vulnerability, including its CVSS score and severity. Defenders should verify the affected scope and severity of the vulnerability and review the supplied official advisory or CVE record to validate vendor

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.