Is CVE-2026-40343 in the CISA KEV catalog?

No. CVE-2026-40343 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-40343?

CVE-2026-40343 has a CVSS v3 base score of 5.8 (MEDIUM).

What is the EPSS score for CVE-2026-40343?

CVE-2026-40343 has an EPSS score of 9.96% (95th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix or mitigate CVE-2026-40343?

No published fix for CVE-2026-40343 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

CVE & CISA-KEV Catalog

CVE-2026-40343

MEDIUMEPSS 95th pctl

5.8

CVSS v3

NVD

Description

free5GC UDR is the user data repository (UDR) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.2, a fail-open request handling flaw in the UDR service causes the `/nudr-dr/v2/policy-data/subs-to-notify` POST handler to continue processing requests even after request body retrieval or deserialization errors. This may allow unintended creation of Policy Data notification subscriptions with invalid, empty, or partially processed input, depending on downstream processor behavior. As of time of publication, a patched version is not available.

CWE-754

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeChanged

Impact

ConfidentialityNone

IntegrityLow

AvailabilityNone

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

Exploit Intelligence

9.96%probability of exploitation in 30 days

95thpercentile

Very high risk: more likely to be exploited than 95% of all known CVEs.

References

Patch1

github.com

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.