CVE-2026-23831
Rekor COSE v0.0.1 Canonicalize crashes when passed empty Message
Description
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.
INFO
Published Date :
Jan. 22, 2026, 10:16 p.m.
Last Modified :
Feb. 2, 2026, 3:06 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update Rekor to version 1.5.0 or later.
- Ensure attacker-controlled input is validated before processing.
Public PoC/Exploit Available at Github
CVE-2026-23831 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-23831.
| URL | Resource |
|---|---|
| https://github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd | Patch |
| https://github.com/sigstore/rekor/releases/tag/v1.5.0 | Product Release Notes |
| https://github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-23831 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-23831
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Organization profile and community health files
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-23831 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-23831 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 02, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:linuxfoundation:rekor:*:*:*:*:*:*:*:* versions up to (excluding) 1.5.0 Added Reference Type GitHub, Inc.: https://github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd Types: Patch Added Reference Type GitHub, Inc.: https://github.com/sigstore/rekor/releases/tag/v1.5.0 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833 Types: Vendor Advisory -
New CVE Received by [email protected]
Jan. 22, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-476 Added Reference https://github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd Added Reference https://github.com/sigstore/rekor/releases/tag/v1.5.0 Added Reference https://github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833