What’s Vulnerable › Vulnerabilities

CVE-2026-1837: libjxl: Out-of-bounds write in grayscale color transformation when using LCMS2

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-02-11 · updated 2026-07-15
• Weakness: CWE-805

Description

A specially-crafted file can cause libjxl's decoder to write pixel data to uninitialized unallocated memory. Soon after that data from another uninitialized unallocated region is copied to pixel data. This can be done by requesting color transformation of grayscale images to another grayscale color space. Buffers allocated for 1-float-per-pixel are used as if they are allocated for 3-float-per-pixel. That happens only if LCMS2 is used as CMS engine. There is another CMS engine available (selected by build flags).

Affected products

• libjxl: from 0.9.0 through 0.11.1

References

• https://github.com/libjxl/libjxl/issues/4549
• https://access.redhat.com/security/cve/CVE-2026-1837
• https://bugzilla.redhat.com/show_bug.cgi?id=2438974
• https://github.com/libjxl/libjxl/issues/4549
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-1837.json

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