pypdf: Possible infinite loop during recovery attempts in DictionaryObject.read_from_stream
Priority LOW 22CWE-835Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 2 fixed, 4 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-835.
Summary
pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.2 have a vulnerability in which an attacker can craft a PDF which leads to an infinite loop. This requires reading a file in non-strict mode. This has been fixed in pypdf 6.9.2. If users cannot upgrade yet, consider applying the changes from the patch manually.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00472 41st percentileScored 2026-11-07
Fix Partial pypdf (py-pdf): 6.9.2pypdf (PyPI): 6.9.2Red Hat: 2 advisoriesRed Hat: 2 fixed, 4 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| py-pdf | pypdf | before 6.9.2 | 6.9.2 | Patch available | CNA |
| — | pypdf (PyPI) | before 6.9.2 | 6.9.2 | Patch available | GHSA-87mj-5ggw-8qc3 |
- pypdf Vendorpy-pdf Affected before 6.9.2 Fixed in 6.9.2 Patch available CNA
- pypdf (PyPI) Vendor— Affected before 6.9.2 Fixed in 6.9.2 Patch available GHSA-87mj-5ggw-8qc3
Remediation
- Fix · CNA pypdf (py-pdf) Fixed in 6.9.2
- Fix · GHSA-87mj-5ggw-8qc3 pypdf (PyPI) Fixed in 6.9.2 Advisory →
Red Hat 2 advisories
- RHSA-2026:42644 Released 2026-07-21 · Red Hat rating ImportantRHOAI 2.25.9 - Red Hat OpenShift AI
- Red Hat OpenShift AI 2.25 registry.redhat.io/rhoai/odh-caikit-tgis-serving-rhel9, registry.redhat.io/rhoai/odh-feature-server-rhel9, registry.redhat.io/rhoai/odh-kserve-storage-initializer-rhel9 +36
- RHSA-2026:37275 Released 2026-07-09 · Red Hat rating CriticalRHOAI 3.3.5 - Red Hat OpenShift AI
- Red Hat OpenShift AI 3.3 registry.redhat.io/rhoai/odh-dashboard-rhel9, registry.redhat.io/rhoai/odh-data-science-pipelines-operator-controller-rhel9, registry.redhat.io/rhoai/odh-feast-operator-rhel9 +45
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Lightspeed Core | Affected | No fix yet |
| OpenShift Lightspeed | Affected | No fix yet |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix yet |
| Red Hat OpenShift AI 2.25 | Fixed | RHSA-2026:42644 |
| Red Hat OpenShift AI 3.3 | Fixed | RHSA-2026:37275 |
Not affected: 3 products
- OpenShift Lightspeed
- Red Hat OpenShift AI 2.25
- Red Hat OpenShift AI 3.3
Timeline
- 2026-10-02 Threatist record created from CVE-2026-33699
- 2026-10-03 Alias added: GHSA-87mj-5ggw-8qc3
- 2026-11-06 Fix available: RHSA-2026:42644 · Red Hat
References
More py-pdf Pypdf vulnerabilities
- TI-2023-18601 Infinite Loop when reading malformed objects in pypdf CVSS 3.1MEDIUM 6.5
- TI-2023-18305 Infinite Loop when a comment isn't followed by a character in pypdf CVSS 3.1MEDIUM 6.2
- TI-2026-42743 pypdf: Possible infinite loop for not terminated inline images CVSS 4.0HIGH 8.7
- TI-2026-42742 pypdf: Possible infinite loop for not terminated inline images (ASCII85 and ASCIIHex filter) CVSS 4.0HIGH 8.7
- TI-2026-65557 pypdf: Possible large memory usage when retrieving alphabetical page labels CVSS 4.0HIGH 8.7
- TI-2026-65556 pypdf: Possible long runtimes with large amount of embedded files CVSS 4.0HIGH 8.7
Sources
- CVE-2026-33699 · CVE Program
- CVE-2026-33699 · NVD
- FIRST EPSS
- GHSA-87mj-5ggw-8qc3 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-33699 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences