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Fencer Vulns
high 7.5

CVE-2026-102997 json

pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)

published 2026-09-30 39 d ago modified 2026-11-02 7 d ago also EUVD-2026-90373 , GHSA-jw7q-gvrg-4vj3 , PYSEC-2026-4156

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 27%
public exploits
0
none known

Summary

pypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF containing a partially malformed /FlateDecode stream with padded data can force pypdf/filters.py to use inefficient byte-by-byte decompression while the earlier recovery counter fails to advance for bytes that successfully decode, causing long runtimes and application unavailability. This is a residual issue after the malformed FlateDecode recovery fix. This issue is fixed in version 6.18.1.

Patch / fix

  • pypi pypdf 6.18.1
  • py-pdf pypdf 6.18.1
  • pypdf2_project pypdf2 6.18.1
  • pypdf_project pypdf 6.18.1
  • pypdf Debian 14 6.19.0-1

debian advisories DEBIAN-CVE-2026-102997

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-2026-102997 updated cvss 7.5

pypdf: pypdf: Denial of Service via crafted FlateDecode stream

  • Red Hat Ansible Automation Orchestrator 2026 ansible-automation-platform/automation-orchestrator-backend-rhel9 Red Hat Lightspeed Core lightspeed-core/rag-tool-cpu-rhel9, lightspeed-core/lightspeed-stack-rhel9, lightspeed-core/rag-tool-cuda-12.9-rhel9
    affected: workaround, no fix available
  • Red Hat Ansible Automation Platform 2 ansible-automation-platform-25/lightspeed-chatbot-rhel8
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-gaudi-rhel9, rhelai3/disk-image-cuda-rhel9
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-ogx-core-rhel9, rhoai/odh-llama-stack-core-rhel9 Red Hat Quay 3 quay/quay-rhel8, quay/quay-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-ocp-rag-rhel9, openshift-lightspeed-tech-preview/lightspeed-rag-tool-rhel9
    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
none
Automatable
no
Technical impact
partial
Assessed
38 d ago

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
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
<6.18.1
6.18.1

Affected products

  • py-pdf pypdf

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-407 Inefficient Algorithmic Complexity

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.