Vulnerability Report

CVE-2026-23831

Title: Nil Pointer Dereference in Rekor Entry Canonicalization

Memory Corruption

Proof Of Concept

No public PoC currently indexed for CVE-2026-23831.

CWE Category CWE-476
Published Date Jan 22, 2026
Modified Date Feb 02, 2026
Exploit Status Not Found
Score 5.3 CVSS v3.1
Exploit Probability (EPSS)
0.02%

Vulnerability Summary

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.

Impacted Vendors

L
linuxfoundation 1

Reference Links

https://github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd https://github.com/sigstore/rekor/releases/tag/v1.5.0 https://github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.3
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-23831 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected Stack

No specific products linked.