Rekor COSE v0.0.1 Canonicalize crashes when passed empty Message

Open Source Vulnerabilities CVE-2026-23831

Rekor is a software supply chain transparency log. In versions 1.4.3 and below, the entry implementation can panic on attacker-controlled input when canonicalizing a proposed entry with an empty spec.message, causing nil Pointer Dereference. Function validate() returns nil (success) when message is empty, leaving sign1Msg uninitialized, and Canonicalize() later dereferences v.sign1Msg.Payload. A malformed proposed entry of the cose/v0.0.1 type can cause a panic on a thread within the Rekor process. The thread is recovered so the client receives a 500 error message and service still continues, so the availability impact of this is minimal. This issue has been fixed in version 1.5.0.

Open Source Vulnerabilities GHSA-273p-m2cw-6833

## Summary Rekor’s cose v0.0.1 entry implementation can panic on attacker-controlled input when canonicalizing a proposed entry with an empty `spec.message`. `validate()` returns nil (success) when `message` is empty, leaving `sign1Msg` uninitialized, and `Canonicalize()` later dereferences `v.sign1Msg.Payload`. ## Impact A malformed proposed entry of the `cose/v0.0.1` type can cause a panic on a thread within the Rekor process. The thread is recovered so the client receives a 500 error message and service still continues, so the availability impact of this is minimal. ## Patches Upgrade to v1.5.0 ## Workarounds None

Open Source Vulnerabilities GO-2026-4354

Rekor's COSE v0.0.1 entry type nil pointer dereference in Canonicalize via empty Message in github.com/sigstore/rekor