Open5GS transfer-update denial of service

published 2026-05-01 6 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-26468

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits: 0; none known

A vulnerability was found in Open5GS up to 2.7.7. This affects the function amf_namf_comm_handle_registration_status_update_request in the library /lib/app/ogs-init.c of the file /namf-comm/v1/ue-contexts/{ueContextId}/transfer-update. Performing a manipulation of the argument ueContextId results in denial of service. The attack can be initiated remotely. The exploit has been made public and could be used. The project was informed of the problem early through an issue report but has not responded yet.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 6 mo ago (2026-05-04)

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/open5gs/open5gs/issues/4399 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
CNA	3.0	4.3	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
CNA	2.0	4.0	AV:N/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR
CNA	4.0	2.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CNA	2.0	4.0	AV:N/AC:L/Au:S/C:N/I:N/A:P

Affected products

n/a Open5GS

Classification

Weakness

CWE-404 Improper Resource Shutdown or Release

References

github.com /open5gs/open5gs/issues/4399
exploit, issue-tracking
vuldb.com /vuln/360352
vdb-entry, technical-description
vuldb.com /vuln/360352/cti
signature, permissions-required
vuldb.com /submit/804291
third-party-advisory
vuldb.com /submit/804303
third-party-advisory
github.com /open5gs/open5gs/
product

Sources

CVE List CVE-2026-7535
NVD CVE-2026-7535

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