PT-2026-4280 · Rekor · Rekor

1Seal · Published 2026-01-22 · Updated 2026-04-16 · CVE-2026-23831

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Name of the Vulnerable Software and Affected Versions Rekor versions 1.4.3 and below

Description Rekor’s entry implementation can experience a panic when processing attacker-controlled input during the canonicalization of a proposed entry with an empty spec.message. The validate() function incorrectly returns success when the message is empty, resulting in an uninitialized sign1Msg. Subsequently, the Canonicalize() function attempts to dereference v.sign1Msg.Payload, leading to a nil pointer dereference. A malformed proposed entry of the cose/v0.0.1 type can trigger this panic within the Rekor process. The service recovers from the panic, returning a 500 error to the client, minimizing the impact on availability.

Recommendations Upgrade to version 1.5.0.

Exploit

Fix

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

CLEANSTART-2026-EZ47382

CLEANSTART-2026-GK29346

CLEANSTART-2026-WB12909

CVE-2026-23831

GHSA-273P-M2CW-6833

GO-2026-4354

OPENSUSE-SU-2026:10127-1

SUSE-SU-2026:0403-1

Affected Products

Rekor

References · 175

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23831.json · Exploit
• https://github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd · Patch
• https://github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-32281 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2025-15558 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-23991 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-22039 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-1229 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-33186 · Security Note
• https://osv.dev/vulnerability/CLEANSTART-2026-GK29346 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-26958 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-32289 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-23881 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2025-66564 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-33810 · Security Note