NULL pointer dereference in Linuxfoundation Rekor
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.004 (35.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
- Linuxfoundation Rekor
- Sigstore Rekor — versions < 1.5.0
Weakness classification (CWE)
References
- github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833 (Vendor Advisory)
- github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd (Patch)
- github.com/sigstore/rekor/releases/tag/v1.5.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-23831?
- CVE-2026-23831 is a medium-severity vulnerability in Linuxfoundation Rekor, classified under NULL Pointer Dereference. CVSS score: 5.3/10. Published 2026-01-22.
- How severe is CVE-2026-23831?
- Medium severity. CVSS v3 base score is 5.3 out of 10.