Cyber Resilience

CVE-2026-41312

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 0.0023 13th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-41312 is a medium-severity Memory Allocation with Excessive Size Value (CWE-789) 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 13th 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 SI-10 (Information Input Validation) 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 the RAM being exhausted. This requires accessing a stream compressed using `/FlateDecode`…

more

with a `/Predictor` unequal 1 and large predictor parameters. 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-2026-41314Same product: Pypdf Project Pypdf
CVE-2026-59938Same product: Pypdf Project Pypdf
CVE-2026-41313Same product: Pypdf Project Pypdf
CVE-2025-62707Same product: Pypdf Project Pypdf
CVE-2026-49460Same product: Pypdf Project Pypdf
CVE-2026-41168Same product: Pypdf Project Pypdf
CVE-2026-27025Same product: Pypdf Project Pypdf
CVE-2023-36810Same product: Pypdf Project Pypdf
CVE-2026-40260Same product: Pypdf Project Pypdf
CVE-2025-62708Same product: Pypdf Project Pypdf

Affected Assets

pypdf project
pypdf
≤ 6.10.2

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Input validation directly rejects or bounds untrusted size values before any allocation occurs.

Resource quotas and priority allocation limit the system-wide impact of an oversized request.

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 coding flaws that trust unvalidated size values for allocations.

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 in development can detect and block excessive allocation flaws before deployment.

prevents

Secure development lifecycle includes input validation and size checks that prevent unbounded allocations.

prevents

Application security requirements mandate bounds checking on size parameters to avoid excessive memory allocation.

prevents

Secure architecture principles require resource-limit enforcement that mitigates uncontrolled memory requests.

prevents

Secure coding standards directly prohibit allocating memory from untrusted size values without validation.

none

Capacity management monitors overall resource use but does not prevent individual allocation bugs.

References