Skip to content

SixLabors ImageSharp Has Infinite Loop in GIF Decoder When Skipping Malformed Comment Extension Blocks

Moderate severity GitHub Reviewed Published Jul 30, 2025 in SixLabors/ImageSharp • Updated Jul 31, 2025

Package

nuget SixLabors.ImageSharp (NuGet)

Affected versions

< 2.1.11
>= 3.0.0, < 3.1.11

Patched versions

2.1.11
3.1.11

Description

Impact

A specially crafted GIF file containing a malformed comment extension block (with a missing block terminator) can cause the ImageSharp GIF decoder to enter an infinite loop while attempting to skip the block. This leads to a denial of service. Applications processing untrusted GIF input should upgrade to a patched version.

Patches

The problem has been patched. All users are advised to upgrade to v3.1.11 or v2.1.11.

Workarounds

None.

References

@JimBobSquarePants JimBobSquarePants published to SixLabors/ImageSharp Jul 30, 2025
Published to the GitHub Advisory Database Jul 30, 2025
Reviewed Jul 30, 2025
Published by the National Vulnerability Database Jul 30, 2025
Last updated Jul 31, 2025

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(16th percentile)

Weaknesses

Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. Learn more on MITRE.

Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Learn more on MITRE.

CVE ID

CVE-2025-54575

GHSA ID

GHSA-rxmq-m78w-7wmc

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.