CVE-2026-39395VulnerabilityPublished 22 Jun 2026Updated 16 Sep 2026

SUSE cosign · Security update for cosign

Affects SUSE cosignSource GCVE Database

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Authoritative record:CVE-2026-39395· Medium 4.3

Not known to be exploited · CVSS 4.3 Medium · fixed in SUSE package updates : update SUSE cosign when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.0.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 7 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
SUSEsuse/cosign`pkg:rpm/suse/cosign`Other threats	Affected =3.0.6-150400.3.42.1	Fixed in–

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AI-suggested

Upgrade to cosign version 3.0.5 or later as provided by the SUSE Product Security Team. This update fixes the incorrect attestation verification issue. No additional mitigation steps are indicated.

Description

A security update for cosign addresses CVE-2026-39395, which involves incorrect attestation verification caused by malformed payloads or mismatched predicate types. This vulnerability could affect the integrity of attestation processes. The update also includes a non-security version upgrade to 3.0.5. The severity of this issue is assessed as medium.

Impact

The vulnerability allows incorrect verification of attestations, which may compromise the reliability of attestation-based security mechanisms. This could affect systems relying on cosign for secure signing and verification, potentially allowing invalid attestations to be accepted.

Summary

CVE-2026-39395 is a vulnerability in cosign where attestation verification can be incorrect due to malformed payloads or mismatched predicate types. This flaw could lead to improper validation of attestations, potentially undermining trust in the attestation process. The update to cosign version 3.0.5 fixes this issue. No CVSS score is provided, and no known exploits are reported in the wild.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Sep 2026, 03:23 UTC

Technical details

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