PatchSiren cyber security CVE debrief
CVE-2026-8813 ExifReader CVE debrief
A denial-of-service vulnerability exists in ExifReader versions prior to 4.39.0. The issue stems from improper handling of ICC mluc (multi-localized Unicode) tags in image metadata parsing. When a crafted image contains an mluc tag with an attacker-controlled record count paired with a zero record size, the parser enters a loop that repeatedly processes the same record and appends entries to an array without adequate bounds checking. This leads to unbounded memory growth, potentially causing memory exhaustion and application crash in services that process untrusted images. The vulnerability is remotely exploitable without authentication, making it particularly relevant for web applications and image processing pipelines that accept user-uploaded content.
- Vendor
- ExifReader
- Product
- ExifReader
- CVSS
- HIGH 7.7
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-05-19
- Original CVE updated
- 2026-05-19
- Advisory published
- 2026-05-19
- Advisory updated
- 2026-05-19
Who should care
Organizations running web applications, content management systems, or image processing pipelines that use ExifReader to parse metadata from user-uploaded images are at risk. This includes e-commerce platforms, social media applications, document management systems, and any Node.js-based service performing EXIF extraction on untrusted image files.
Technical summary
The vulnerability resides in ExifReader's ICC profile parser, specifically in the handling of multi-localized Unicode (mluc) tags. The mluc tag structure contains a record count and record size field. When record size is zero but record count is non-zero (attacker-controlled), the parser's loop condition fails to advance properly, causing repeated processing of the same record location. Each iteration appends data to a result array without validating against reasonable bounds. This results in memory allocation growing linearly with the attacker-specified record count, leading to resource exhaustion. The fix commit modifies the parsing logic to validate record size and prevent the unbounded loop condition.
Defensive priority
HIGH
Recommended defensive actions
- Upgrade ExifReader to version 4.39.0 or later to obtain the fix for ICC mluc tag parsing
- Review applications that process user-supplied images with ExifReader to identify potentially vulnerable deployments
- Implement resource limits and timeouts for image processing operations as defense in depth
- Consider input validation to reject images with suspicious ICC profile structures before parsing
- Monitor memory usage patterns in image processing services for anomalous growth indicative of exploitation attempts
Evidence notes
The vulnerability is classified under CWE-1284 (Improper Validation of Specified Quantity in Input). The CVSS 4.0 vector indicates network attack vector with low attack complexity, no privileges required, and high availability impact. The NVD entry currently shows a status of 'Deferred'. The fix commit addresses the parsing logic for ICC profile mluc tags.
Official resources
CVE-2026-8813 was published on 2026-05-19T07:16:30.193Z and subsequently modified on 2026-05-19T15:38:48.397Z. The vulnerability was reported through Snyk's security disclosure process. A fix has been committed to the ExifReader repository.