Skip to content
Fencer Vulns
high 7.5

CVE-2026-27628 json

pypdf has a possible infinite loop when loading circular /Prev entries in cross-reference streams

published 2026-02-25 8 mo ago modified 2026-11-02 6 d ago also GHSA-2rw7-x74f-jg35 , PYSEC-2026-3005 , EUVD-2026-8601

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

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. As a workaround, one may apply the patch manually.

Patch / fix

  • pypi pypdf 6.7.2
  • py-pdf pypdf 6.7.2
  • pypdf Debian 14 6.9.0-1

debian advisories DEBIAN-CVE-2026-27628

  • python-PyPDF2 openSUSE Tumbleweed 2.11.1-5.1

opensuse advisories openSUSE-SU-2026:10284-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-27628 updated cvss 7.5

pypdf: possible infinite loop when loading circular /Prev entries in cross-reference streams

  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-ocp-rag-rhel9, openshift-lightspeed/lightspeed-service-api-rhel9, openshift-lightspeed-tech-preview/lightspeed-rag-tool-rhel9
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/disk-image-cuda-rhel9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat OpenShift AI 2.25 rhoai 1775144403
    fixed: vendor fix RHSA-2026:10184
  • Red Hat Quay 3.9 quay 1773936323
    fixed: vendor fix RHSA-2026:5168
  • Red Hat Quay 3.10 quay 1773971077
    fixed: vendor fix RHSA-2026:5665
  • Red Hat Quay 3.12 quay 1773771962
    fixed: vendor fix RHSA-2026:4942
  • Red Hat Quay 3.15 quay 1775169219
    fixed: vendor fix RHSA-2026:6568
  • Red Hat Quay 3.16 quay 1775069491, quay 1775169226
    fixed: vendor fix RHSA-2026:6497
show 1 more
  • Red Hat OpenShift AI 2.25 rhoai 1776243157, rhoai 1776243163, rhoai 1776243192, rhoai 1776243217, rhoai 1776243229, rhoai 1776243238, +70 more Red Hat Quay 3.9 quay 1772725093, quay 1772728539, quay 1772739181, quay 1773931180, quay 1773931187, quay 1773931200, +3 more Red Hat Quay 3.10 quay 1772725047, quay 1772726823, quay 1772739218, quay 1774021695, quay 1774021704, quay 1774021722, +3 more Red Hat Quay 3.12 quay 1772054192, quay 1772054202, quay 1772132933, quay 1773761676, quay 1773765467, quay 1773765477, +3 more Red Hat Quay 3.15 quay 1774979159, quay 1774979227, quay 1774980222, quay 1774980224, quay 1774984603, quay 1775183105, +3 more Red Hat Quay 3.16 quay 1773781267, quay 1773784956, quay 1773784969, quay 1773784980, quay 1773785008, quay 1773785412, +10 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
8 mo ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/py-pdf/pypdf/issues/3654 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 1.2 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
CNA 4.0 1.2 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:X
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi pypdf
<6.7.2
6.7.2

Affected products

  • py-pdf pypdf

Classification

Weakness
  • CWE-835 Loop with Unreachable Exit Condition

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.