Cyber Resilience

CVE-2026-41313

DoS in Pypdf Project Pypdf ≤ 6.10.2

Published
22 April 2026
Modified
27 April 2026
Patch / advisory
CVSS Score v4 4.8
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0021 12th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-41313 is a medium-severity Excessive Iteration (CWE-834) vulnerability in Pypdf Project Pypdf. Its CVSS base score is 4.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 12th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-8 (Security and Privacy Engineering Principles) and SC-6 (Resource Availability) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.2 can craft a PDF which leads to long runtimes. This requires loading a PDF with a large trailer `/Size`…

more

value in incremental mode. This has been fixed in pypdf 6.10.2. As a workaround, one may apply the changes from the patch manually.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-48156Same product: Pypdf Project Pypdf
CVE-2025-62707Same product: Pypdf Project Pypdf
CVE-2026-27025Same product: Pypdf Project Pypdf
CVE-2026-41168Same product: Pypdf Project Pypdf
CVE-2026-59938Same product: Pypdf Project Pypdf
CVE-2025-62708Same product: Pypdf Project Pypdf
CVE-2026-28804Same product: Pypdf Project Pypdf
CVE-2023-36810Same product: Pypdf Project Pypdf
CVE-2026-41312Same product: Pypdf Project Pypdf
CVE-2026-40260Same product: Pypdf Project Pypdf

Affected Assets

pypdf project
pypdf
≤ 6.10.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Engineering principles can require developers to bound all loops and iterations at design time.

Resource quotas limit the CPU/time impact of an excessively long loop without eliminating the flaw.

Input validation can reject or sanitize data that would otherwise drive unbounded iteration.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent unbounded loops via code review, static analysis, and testing.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect excessive iteration through stress and fuzz testing.

prevents

Secure development lifecycle requires input validation and loop bounds, directly limiting excessive iteration.

prevents

Application security requirements include resource-consumption limits that prevent unbounded loops.

prevents

Secure architecture principles mandate defensive coding patterns such as loop termination checks.

prevents

Secure coding standards explicitly forbid unbounded loops and require explicit iteration limits.

References