CVE-2026-42082: free5GC: Missing Concurrent NAS SMC Validation During NGAP Handover
Vulnerability summary
CVE-2026-42082 is a medium (CVSS 5.4) vulnerability in free5gc. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.5% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 27-05-2026PublishedVulnerability first disclosed.
- 28-05-2026Last modifiedVulnerability information updated.
Description
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, the AMF in Free5GC does not enforce the concurrent security procedure rules defined in 3GPP TS 33.501 §6.9.5.1. The AMF does not check for ongoing N2 handover procedures before initiating a NAS Security Mode Command, and vice versa. This can lead to mismatches between NAS and AS security contexts in the network and the UE. This vulnerability is fixed in 4.2.2.
CVSS metrics
3 scores · 3 sources · 1 version- CVE.orgCNA3.7LowCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:LDiffers
- OSV · GoEcosystem advisory · calculated3.7LowCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:LDiffers
EPSS trend
Probability
0.25%
Chance of exploitation in the next 30 days
Percentile
16%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.25% on 22-09-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundFree5Gc
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Free5gc1 product
- free5gc< 4.2.2
Github.com/free5gc1 product
- amf≤ 1.4.3 | All versions (No fix recorded)
2 vendors · 2 products
References
5 links- github.com/free5gc/free5gc/security/advisories/GHSA-vrrx-58h3-prmhX Refsource CONFIRMWEBAdvisoryExploitVendor Advisory
- github.com/free5gc/free5gcPACKAGE