Pillow before 8.1.2 allows attackers to cause a denial of service (memory consumption)…
Priority LOW 38CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- 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-400.
Summary
Pillow before 8.1.2 allows attackers to cause a denial of service (memory consumption) because the reported size of a contained image is not properly checked for an ICO container, and thus an attempted memory allocation can be very large.
Why it matters now
EPSS 0.03045 87th percentileScored 2026-11-07
Fix Partial pillow (PyPI): 8.1.2Red 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) | before 8.1.2 | 8.1.2 | Patch available | GHSA-95q3-8gr9-gm8w |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- pillow (PyPI) Vendor— Affected before 8.1.2 Fixed in 8.1.2 Patch available GHSA-95q3-8gr9-gm8w
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* | before 8.1.1 | Vulnerable | python-pillow |
| cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* | 32 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* | 33 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 34 | Vulnerable | Fedoraproject |
- cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* Versions before 8.1.1 Vulnerable ·python-pillow
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* Versions 32 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
Remediation
- Fix · GHSA-95q3-8gr9-gm8w pillow (PyPI) Fixed in 8.1.2 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-2021-27923
- 2026-10-03 Alias added: GHSA-95q3-8gr9-gm8w
References
Advisory 7
Other 10
- https://pillow.readthedocs.io/en/stable/releasenotes/8.1.2.html
- https://github.com/python-pillow/Pillow/commit/756fff33128a0b643d10518a26ad04b726dd8973
- https://github.com/pypa/advisory-database/tree/main/vulns/pillow/PYSEC-2021-42.yaml
- https://github.com/python-pillow/Pillow
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S7G44Z33J4BNI2DPDROHWGVG2U7ZH5JU
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TQQY6472RX4J2SUJENWDZAWKTJJGP2ML
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZTSY25UJU7NJUFHH3HWT575LT4TDFWBZ
- https://lists.fedoraproject.org/archives/list/[email protected]/message/S7G44Z33J4BNI2DPDROHWGVG2U7ZH5JU
- https://lists.fedoraproject.org/archives/list/[email protected]/message/TQQY6472RX4J2SUJENWDZAWKTJJGP2ML
- https://lists.fedoraproject.org/archives/list/[email protected]/message/ZTSY25UJU7NJUFHH3HWT575LT4TDFWBZ
Sources
- CVE-2021-27923 · CVE Program
- CVE-2021-27923 · NVD
- FIRST EPSS
- GHSA-95q3-8gr9-gm8w · GitHub Advisory Database · CC BY 4.0
- CVE-2021-27923 · 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