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.
CVE-2026-4240
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory enrichment pending alignment with NVD CVSS.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(low)
- EG Risk
- 38(Track)EG Risk 38/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
Published
March 16, 2026
Last Modified
June 17, 2026
References (8)
- cna@vuldbhttps://github.com/open5gs/open5gs/
- cna@vuldbhttps://github.com/open5gs/open5gs/commit/80eb484a6ab32968e755e628b70d1a9c64f012ec
- cna@vuldbhttps://github.com/open5gs/open5gs/issues/4343
- cna@vuldbhttps://github.com/open5gs/open5gs/issues/4343#issue-4021871895
- cna@vuldbhttps://github.com/open5gs/open5gs/releases/tag/v2.7.7
- cna@vuldbhttps://vuldb.com/?ctiid.351182
- cna@vuldbhttps://vuldb.com/?id.351182
- cna@vuldbhttps://vuldb.com/?submit.771361
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 3× in last 7d / 3× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-27 14:43 UTCEG score recompute
- 2026-07-27 14:43 UTCGHSA enrichment
- 2026-07-27 14:27 UTCOSV refresh
Related CVEs(same CWE)
Same CWE
10 shownCWE-404
- CVE-2018-8639NVD 7.8EG 9.0 KEVEPSS p97CRITICAL
- CVE-2018-8611NVD 7.8EG 9.0 KEVEPSS p90CRITICAL
- CVE-2018-8453NVD 7.8EG 9.0 KEVEPSS p99CRITICAL
- CVE-2018-8406NVD 7.8EG 9.0 KEVCRITICAL
- CVE-2018-8405NVD 7.8EG 9.0 KEVCRITICAL
- CVE-2018-8120NVD 7.0EG 9.0 KEVEPSS p99CRITICAL
- CVE-2017-6627NVD 7.5EG 9.0 KEVEPSS p93CRITICAL
- CVE-2018-8450EG 8.8EPSS p97HIGH
- CVE-2019-1708EG 8.6HIGH
- CVE-2019-1706EG 8.6HIGH
Frequently asked(4)
What is CVE-2026-4240?
When was CVE-2026-4240 disclosed?
What is the CVSS score of CVE-2026-4240?
How do I remediate CVE-2026-4240?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-4240
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