What’s Vulnerable › Vulnerabilities

CVE-2026-42500: Panic when reading out of bound palette index in golang.org/x/image/bmp

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-29 · updated 2026-07-22

Description

Decoding a paletted BMP file with an out-of-range palette index results in a panic when accessing pixels in the invalid image.

Affected products

• golang.org/x/image/bmp: before 0.41.0 — fixed in 0.41.0

How to fix

Upgrade to a fixed version: golang.org/x/image/bmp 0.41.0. Check the vendor advisory for mitigations.

References

• https://go.dev/cl/781500
• https://go.dev/issue/79576
• https://groups.google.com/g/golang-announce/c/uhYX90BlBvI
• https://pkg.go.dev/vuln/GO-2026-5031

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