Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/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:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-27628 is a low-severity Infinite Loop (CWE-835) vulnerability in Pypdf Project Pypdf. Its CVSS base score is 1.2 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 27th 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-11 (Developer Testing and Evaluation) and SI-2 (Flaw Remediation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-27628 is a denial-of-service vulnerability in pypdf, a free and open-source pure-python PDF library. Versions prior to 6.7.2 are affected, where processing a specially crafted PDF file triggers an infinite loop (CWE-835: Loop with Unreachable Exit Condition). The issue has a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), reflecting high availability impact with no requirements for privileges or user interaction.
A remote attacker can exploit this vulnerability by crafting a malicious PDF file and inducing a victim to process it using a vulnerable pypdf installation, such as in a PDF parsing application or service. This leads to an infinite loop during file reading, causing resource exhaustion and denial of service on the affected system or process.
The vulnerability has been fixed in pypdf version 6.7.2. As a workaround, users can manually apply the patch from the referenced commit. Official advisories and discussions are available in the pypdf GitHub security advisory (GHSA-2rw7-x74f-jg35) and related issues.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8601
Vulnerability Data
pypdf is a free and open-source pure-python PDF library. Prior to 6.7.2, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires reading the file. This has been fixed in pypdf 6.7.2.…
more
As a workaround, one may apply the patch manually.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover unreachable loop exit conditions through static analysis, fuzzing, or execution tracing.
Flaw remediation processes identify and correct infinite-loop defects reported from testing or operations.
Requiring documented development processes and secure coding standards reduces introduction of loops whose termination conditions are unreachable.
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.
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.
Security testing can uncover infinite-loop conditions before release.
Secure development life cycle mandates practices that can detect and prevent infinite-loop defects.
Application security requirements can specify loop-termination rules, indirectly reducing the weakness.
Secure coding standards directly address loop termination and prevent infinite loops.