How severe is CVE-2026-23831?

CVE-2026-23831 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-23831 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-23831?

CVE-2026-23831 affects Linuxfoundation Rekor. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-23831?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-23831 have an EU (EUVD) identifier?

Yes. CVE-2026-23831 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3809.

When was CVE-2026-23831 published?

CVE-2026-23831 was published on 2026-01-22 and last updated on 2026-06-17.

CVE-2026-23831

CVE-2026-23831 is a medium-severity vulnerability in Linuxfoundation Rekor with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-3809
Weakness: CWE-476
Affected product: Linuxfoundation Rekor
Published: 2026-01-22
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-23831?: CVE-2026-23831 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-23831 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23831?: CVE-2026-23831 affects Linuxfoundation Rekor. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-23831?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-23831 have an EU (EUVD) identifier?: Yes. CVE-2026-23831 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3809.
When was CVE-2026-23831 published?: CVE-2026-23831 was published on 2026-01-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:linuxfoundation:rekor:*:*:*:*:*:*:*:*

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