What is the CVSS score of CVE-2026-28231?

CVE-2026-28231 has a CVSS 3.1 base score of 9.1 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H. EPSS exploitation probability: 0.1%.

Which versions of Python are affected by CVE-2026-28231?

A critical vulnerability in the pillow_heif Python library (CVSS 9.1) could allow attackers to execute arbitrary code through specially crafted HEIF image files.. A patch is available.

Is there a public PoC exploit available for CVE-2026-28231?

Yes, a public proof-of-concept exploit is available for CVE-2026-28231. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-28231?

Within 24 hours: Identify all systems and applications using pillow_heif through dependency scanning and asset inventory. Within 7 days: Apply the available vendor patch to all affected environments and test in staging before production deployment. Within 30 days: Conduct a post-incident review, verify patch deployment across all systems, and implement automated dependency vulnerability monitoring to prevent future gaps.

Python CVE-2026-28231

CRITICAL

Out-of-bounds Read (CWE-125)

2026-02-27 security-advisories@github.com

Python Integer Overflow Denial Of Service Information Disclosure Pillow Heif Suse

9.1

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

9.1 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

SUSE

CRITICAL

qualitative

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

PoC Detected

Mar 04, 2026 - 15:55 vuln.today

Public exploit code

Patch released

Mar 04, 2026 - 15:55 nvd

Patch available

CVE Published

Feb 27, 2026 - 20:21 nvd

CRITICAL 9.1

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

1 pypi packages depend on pi-heif (1 direct, 0 indirect)
3 pypi packages depend on pillow-heif (2 direct, 1 indirect)

Ecosystem-wide dependent count for version 1.3.0 and other introduced versions.

DescriptionGitHub Advisory

pillow_heif is a Python library for working with HEIF images and plugin for Pillow. Prior to version 1.3.0, an integer overflow in the encode path buffer validation of _pillow_heif.c allows an attacker to bypass bounds checks by providing large image dimensions, resulting in a heap out-of-bounds read. This can lead to information disclosure (server heap memory leaking into encoded images) or denial of service (process crash). No special configuration is required - this triggers under default settings. Version 1.3.0 fixes the issue.

AnalysisAI

Integer overflow in pillow_heif Python library before 1.3.0 leads to out-of-bounds read when processing HEIF images, potentially causing information disclosure or crashes. PoC and patch available.

Technical ContextAI

CWE-125 out-of-bounds read caused by integer overflow in HEIF image dimension handling. pillow_heif is a Pillow plugin for HEIF/HEIC image format support.