CVE-2026-4240

Open5GS CCA smf_s6b_sta_cb denial of service

HIGH
7.5
CVSS Score
Published: March 16, 2026 at 01:32 PM UTC
Updated: June 17, 2026 at 10:56 AM UTC
1 product affected across 1 vendorOpen5GS

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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 2.7.7 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (8)

VDB EntryTechnical DescriptionThird Party Advisory
Source: cverecord
https://vuldb.com/?id.351182
SignaturePermissions RequiredVDB Entry
Source: cverecord
https://vuldb.com/?ctiid.351182
Third Party AdvisoryExploitVDB Entry
Source: cverecord
https://vuldb.com/?submit.771361
Issue TrackingThird Party Advisory
Source: cverecord
https://github.com/open5gs/open5gs/issues/4343
ExploitIssue TrackingThird Party Advisory
Source: cverecord
https://github.com/open5gs/open5gs/issues/4343#issue-4021871895
Product
Source: cverecord
https://github.com/open5gs/open5gs/

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-404

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