How severe is CVE-2026-3739?

CVE-2026-3739 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-3739 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-3739?

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

Does CVE-2026-3739 have an EU (EUVD) identifier?

Yes. CVE-2026-3739 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10242.

When was CVE-2026-3739 published?

CVE-2026-3739 was published on 2026-03-08 and last updated on 2026-06-17.

CVE-2026-3739

CVE-2026-3739 is a medium-severity vulnerability with a CVSS 3.x base score of 6.3. 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-287.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v2: 6.5
CVSS v4: 2.1
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-10242
Weakness: CWE-287
Published: 2026-03-08
Last modified: 2026-06-17

Description

A security flaw has been discovered in suitenumerique messages 0.2.0. This issue affects the function ThreadAccessSerializer of the file src/backend/core/api/serializers.py of the component ThreadAccess. The manipulation results in improper authentication. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks. Upgrading to version 0.3.0 is capable of addressing this issue. The patch is identified as d7729f4b885449f6dee3faf8b5f2a05769fb3d6e. The affected component should be upgraded.

Frequently asked questions

What is CVE-2026-3739?: A security flaw has been discovered in suitenumerique messages 0.2.0. This issue affects the function ThreadAccessSerializer of the file src/backend/core/api/serializers.py of the component ThreadAccess. The manipulation results in improper authentication. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks. Upgrading to version 0.3.0 is capable of addressing this issue. The patch is identified as d7729f4b885449f6dee3faf8b5f2a05769fb3d6e. The affected component should be upgraded.
How severe is CVE-2026-3739?: CVE-2026-3739 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-3739 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-3739?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3739 have an EU (EUVD) identifier?: Yes. CVE-2026-3739 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10242.
When was CVE-2026-3739 published?: CVE-2026-3739 was published on 2026-03-08 and last updated on 2026-06-17.

References

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

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