Free5GC Gmm handler.go race condition

published 2026-09-20 49 d ago modified 2026-09-21 48 d ago also EUVD-2026-83769

cvss: 5.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits: 0; none known

A vulnerability was determined in Free5GC up to 4.2.3. This vulnerability affects unknown code of the file /corefuzzer_deps/free5gc/NFs/amf/internal/gmm/handler.go of the component Gmm Handler. This manipulation causes race condition. The attack can be initiated remotely. Patch name: e323b01464355781b8b8d5dd695e05cbc00a62f2. To fix this issue, it is recommended to deploy a patch.

Patch / fix

links 2

github.com/free5gc/amf@e323b01 commit
github.com/free5gc/amf#238 pull request

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 48 d ago (2026-09-21)

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

vuldb.com https://vuldb.com/submit/949261 referenced PoC, tagged "exploit" by a source, unverified
github.com https://github.com/free5gc/free5gc/issues/1109 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
CNA	3.0	5.3	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
CNA	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C
CNA	4.0	5.5	CVSS:4.0/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
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CNA	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

n/a Free5GC

Classification

Weakness

CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

References

github.com /free5gc/amf/pull/238
issue-tracking, patch
github.com /free5gc/amf/commit/e323b01464355781b8b8d5dd695e05cbc00a62f2
patch
vuldb.com /submit/949261
third-party-advisory, exploit
github.com /free5gc/free5gc/issues/1109
issue-tracking, exploit
vuldb.com /vuln/407972
vdb-entry
vuldb.com /vuln/407972/cti
signature, permissions-required
vuldb.com /cve/CVE-2026-94043
third-party-advisory
github.com /free5gc/free5gc/
product

Sources

CVE List CVE-2026-94043
NVD CVE-2026-94043

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary