CVE-2026-120252 cgohlke CVE debrief

Who should care

Defenders responsible for imagecodecs library maintenance and deployment, as well as developers and users of applications that utilize this library, should be aware of this vulnerability and take steps to verify and update the library to prevent potential crashes.

Why it matters

CVE-2026-120252 is a stack-based buffer overflow vulnerability in the imagecodecs library that can cause crashes from crafted JPEG images. Defenders should verify library versions, implement input validation, and update to fixed versions to prevent potential impact.

• Potential crashes from crafted JPEG images require verification and updates to the imagecodecs library
• Defenders should verify library versions and implement input validation and error handling for JPEG image processing

Technical summary

The imagecodecs library contains a stack-based buffer overflow vulnerability in the lossless JPEG Define Huffman Table parser. This vulnerability can be triggered by a crafted lossless JPEG image, causing a crash in the calling process. The vulnerability is caused by the DHT symbol counts wrapping an 8-bit sum, overflowing the 32-entry HufVal and HufSz stack arrays. Defenders should prioritize verifying and updating the imagecodecs library to prevent potential crashes from crafted JPEG images. The CVE record and NVD entry provide details on the vulnerability, but further verification is needed to determine the full scope of affected versions and potential impact.

Defensive priority

Defenders should prioritize verifying and updating the imagecodecs library to prevent potential crashes from crafted JPEG images.

Recommended defensive actions

• Verify the imagecodecs library version and update to a fixed version if necessary
• Review and monitor imagecodecs library usage in the environment
• Implement input validation and error handling for JPEG image processing
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance

Evidence notes

The vulnerability was discovered in imagecodecs 2023.1.23 through 2026.10.10. The CVE record and NVD entry provide details on the vulnerability, but further verification is needed to determine the full scope of affected versions and potential impact.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.