CVE-2026-23831 | Rekor COSE v0.0.1 Canonicalize crashes when passed empty Message

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: 2026-01-22 Last update: 2026-02-02 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-23831 is rated Low Risk (32/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.38%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23831

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.38% +0.35%
2 2026-01-23 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23831

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-23831

GitHub Security Advisory for CVE-2026-23831

GHSA-273p-m2cw-6833 · Severity: medium · Ecosystem: go — Rekor's COSE v0.0.1 entry type nil pointer dereference in Canonicalize via empty Message

OS Trackers for CVE-2026-23831

vendor priority summary link
alpine — CVE-2026-23831: 1 source package rows (rekor); 20 state rows across 2 repos (3.23-community, edge-community); fixed 0, open 20. https://security.alpinelinux.org/vuln/CVE-2026-23831
debian not yet assigned CVE-2026-23831 not yet assigned priority: Debian including 1 source packages (rekor), 3 status rows across 3 suites (forky, sid, trixie): resolved 2, open 1. https://security-tracker.debian.org/tracker/CVE-2026-23831
redhat medium — https://access.redhat.com/security/cve/CVE-2026-23831
suse medium CVE-2026-23831 severity moderate: SUSE including 26 source package names (apptainer, apptainer-leap, …), 179 product×package rows across 25 product lines (SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS, … (25 product lines)): Known Not Affected 178, Fixed 1. https://www.suse.com/security/cve/CVE-2026-23831/
ubuntu medium CVE-2026-23831 medium priority: Ubuntu including 1 source packages (rekor), 4 status rows across 4 suites (jammy, noble, questing, upstream): DNE 2, needs-triage 2. https://ubuntu.com/security/CVE-2026-23831

Affected software / configurations for CVE-2026-23831

Vendor Product Version Raw CPE
linuxfoundation rekor < 1.5.0 cpe:2.3:a:linuxfoundation:rekor:*:*:*:*:*:*:*:*

References for CVE-2026-23831

cvelogic Threat Intelligence