An issue was discovered in Pillow before 8.1.1.
Priority LOW 32CWE-1333Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 2 fixed, 2 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-1333.
Summary
An issue was discovered in Pillow before 8.1.1. The PDF parser allows a regular expression DoS (ReDoS) attack via a crafted PDF file because of a catastrophic backtracking regex.
Why it matters now
EPSS 0.01727 77th percentileScored 2026-11-07
Fix Partial pillow (PyPI): 8.1.1Red Hat: 2 advisoriesRed Hat: 2 fixed, 2 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | pillow (PyPI) | 5.1.0 to before 8.1.1 | 8.1.1 | Patch available | GHSA-9hx2-hgq2-2g4f |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- pillow (PyPI) Vendor— Affected 5.1.0 to before 8.1.1 Fixed in 8.1.1 Patch available GHSA-9hx2-hgq2-2g4f
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* | before 8.1.1 | Vulnerable | python-pillow |
- cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* Versions before 8.1.1 Vulnerable ·python-pillow
Remediation
- Fix · GHSA-9hx2-hgq2-2g4f pillow (PyPI) Fixed in 8.1.1 Advisory →
Red Hat 2 advisories
- RHSA-2021:4149 Released 2021-11-09 · Red Hat rating Moderatepython-pillow security update
- Red Hat Enterprise Linux AppStream (v. 8) python-pillow-5.1.1-16.el8, python3-pillow-5.1.1-16.el8
- RHSA-2021:3917 Released 2021-10-19 · Red Hat rating ImportantRed Hat Quay v3.6.0 security, bug fix and enhancement update
- Quay v3 quay/quay-rhel8
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Quay v3 | Fixed | RHSA-2021:3917 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2021:4149 |
Not affected: 1 product
- Quay v3
Timeline
- 2026-10-02 Threatist record created from CVE-2021-25292
- 2026-10-03 Alias added: GHSA-9hx2-hgq2-2g4f
References
Advisory 4
Other 5
- https://github.com/python-pillow/Pillow/commit/3bce145966374dd39ce58a6fc0083f8d1890719c
- https://github.com/python-pillow/Pillow/commit/521dab94c7ab72b037bd9a83e9663401e0fd2cee
- https://github.com/python-pillow/Pillow/commit/6207b44ab1ff4a91d8ddc7579619876d0bb191a4
- https://github.com/pypa/advisory-database/tree/main/vulns/pillow/PYSEC-2021-38.yaml
- https://github.com/python-pillow/Pillow
More python-pillow Pillow vulnerabilities
- TI-2026-76627 Out-of-bounds read in Pillow TIFF encoder ColorMap handling CVSS 4.0HIGH 8.8
- TI-2026-76625 Quadratic-time denial of service in Pillow PDF save_all CVSS 4.0HIGH 8.7
- TI-2026-76605 NULL pointer dereference in Pillow's Image.merge function CVSS 4.0HIGH 8.7
- TI-2026-76604 Out-of-bounds read in Pillow TIFF decoding leaks heap memory CVSS 4.0HIGH 8.8
- TI-2026-76602 Double free in Pillow ImagingScaleAffine on allocation failure CVSS 4.0HIGH 8.7
- TI-2026-76600 GIF seek in Pillow keeps rejected size, allowing denial of service CVSS 4.0HIGH 8.7
Sources
- CVE-2021-25292 · CVE Program
- CVE-2021-25292 · NVD
- FIRST EPSS
- GHSA-9hx2-hgq2-2g4f · GitHub Advisory Database · CC BY 4.0
- CVE-2021-25292 · Red Hat security data · CC BY 4.0
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