5.5
MEDIUM CVSS 4.0
CVE-2026-4240
Open5GS CCA smf_s6b_sta_cb denial of service
Description

A vulnerability was determined in Open5GS up to 2.7.6. The affected element is the function smf_gx_cca_cb/smf_gy_cca_cb/smf_s6b_aaa_cb/smf_s6b_sta_cb of the component CCA Handler. This manipulation causes denial of service. The attack can be initiated remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 2.7.7 is sufficient to fix this issue. Patch name: 80eb484a6ab32968e755e628b70d1a9c64f012ec. Upgrading the affected component is recommended.

INFO

Published Date :

March 16, 2026, 2:20 p.m.

Last Modified :

March 16, 2026, 2:53 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-4240 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 MEDIUM [email protected]
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM [email protected]
Solution
Update Open5GS to version 2.7.7 to resolve the denial of service vulnerability.
  • Upgrade Open5GS to version 2.7.7.
  • Apply the patch 80eb484a6ab32968e755e628b70d1a9c64f012ec.
  • Update the CCA Handler component.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-4240 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-4240 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-4240 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-4240 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 16, 2026

    Action Type Old Value New Value
    Added Description A vulnerability was determined in Open5GS up to 2.7.6. The affected element is the function smf_gx_cca_cb/smf_gy_cca_cb/smf_s6b_aaa_cb/smf_s6b_sta_cb of the component CCA Handler. This manipulation causes denial of service. The attack can be initiated remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 2.7.7 is sufficient to fix this issue. Patch name: 80eb484a6ab32968e755e628b70d1a9c64f012ec. Upgrading the affected component is recommended.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
    Added CVSS V2 (AV:N/AC:L/Au:N/C:N/I:N/A:P)
    Added CWE CWE-404
    Added Reference https://github.com/open5gs/open5gs/
    Added Reference https://github.com/open5gs/open5gs/commit/80eb484a6ab32968e755e628b70d1a9c64f012ec
    Added Reference https://github.com/open5gs/open5gs/issues/4343
    Added Reference https://github.com/open5gs/open5gs/issues/4343#issue-4021871895
    Added Reference https://github.com/open5gs/open5gs/releases/tag/v2.7.7
    Added Reference https://vuldb.com/?ctiid.351182
    Added Reference https://vuldb.com/?id.351182
    Added Reference https://vuldb.com/?submit.771361
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.