sigstore rekor up to 1.4.x validate null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.2$0-$5k0.00

Summaryinfo

A vulnerability was found in sigstore rekor up to 1.4.x. It has been classified as problematic. Impacted is the function validate. Performing a manipulation results in null pointer dereference. This vulnerability is identified as CVE-2026-23831. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in sigstore rekor up to 1.4.x. It has been classified as problematic. This affects the function validate. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-23831 since 01/16/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 296220 (Linux Distros Unpatched Vulnerability : CVE-2026-23831), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.5.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 39bae3d192bce48ef4ef2cbd1788fb5770fee8cd is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (296220) and EUVD (EUVD-2026-3809). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.3
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 296220
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-23831

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: rekor 1.5.0
Patch: 39bae3d192bce48ef4ef2cbd1788fb5770fee8cd

Timelineinfo

01/16/2026 CVE reserved
01/23/2026 +7 days Advisory disclosed
01/23/2026 +0 days VulDB entry created
01/23/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-273p-m2cw-6833
Status: Confirmed

CVE: CVE-2026-23831 (🔒)
GCVE (CVE): GCVE-0-2026-23831
GCVE (VulDB): GCVE-100-342501
EUVD: 🔒

Entryinfo

Created: 01/23/2026 08:01
Updated: 01/23/2026 14:26
Changes: 01/23/2026 08:01 (68), 01/23/2026 12:35 (1), 01/23/2026 14:26 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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