How severe is CVE-2026-40248?

CVE-2026-40248 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-40248 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40248?

CVE-2026-40248 affects Free5gc. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-40248?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-40248 have an EU (EUVD) identifier?

Yes. CVE-2026-40248 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23314.

When was CVE-2026-40248 published?

CVE-2026-40248 was published on 2026-04-16 and last updated on 2026-06-17.

CVE-2026-40248

CVE-2026-40248 is a high-severity vulnerability in Free5gc with a CVSS 3.x base score of 7.5. 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-285.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-23314
Weakness: CWE-285
Affected product: Free5gc
Published: 2026-04-16
Last modified: 2026-06-17

Description

free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the handler for creating or updating Traffic Influence Subscriptions checks whether the influenceId path segment equals subs-to-notify, but does not return after sending the HTTP 404 response when validation fails. Execution continues and the subscription is created or overwritten regardless. An unauthenticated attacker with access to the 5G Service Based Interface can create or overwrite arbitrary Traffic Influence Subscriptions, including injecting attacker-controlled notificationUri values and arbitrary SUPIs, by supplying any value for the influenceId path segment. A patched version was not available at the time of publication.

Frequently asked questions

What is CVE-2026-40248?: free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the handler for creating or updating Traffic Influence Subscriptions checks whether the influenceId path segment equals subs-to-notify, but does not return after sending the HTTP 404 response when validation fails. Execution continues and the subscription is created or overwritten regardless. An unauthenticated attacker with access to the 5G Service Based Interface can create or overwrite arbitrary Traffic Influence Subscriptions, including injecting attacker-controlled notificationUri values and arbitrary SUPIs, by supplying any value for the influenceId path segment. A patched version was not available at the time of publication.
How severe is CVE-2026-40248?: CVE-2026-40248 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-40248 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40248?: CVE-2026-40248 affects Free5gc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-40248?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-40248 have an EU (EUVD) identifier?: Yes. CVE-2026-40248 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23314.
When was CVE-2026-40248 published?: CVE-2026-40248 was published on 2026-04-16 and last updated on 2026-06-17.

References

https://github.com/free5gc/free5gc/security/advisories/GHSA-jgq2-qv8v-5cmj

Affected products (1)

cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*

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