Open5GS NSSF conv.c ogs_sbi_parse_plmn_list denial of service

published 2026-05-08 6 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-28479

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits: 0; none known

A vulnerability has been found in Open5GS up to 2.7.7. The impacted element is the function ogs_sbi_parse_plmn_list in the library /lib/sbi/conv.c of the component NSSF. The manipulation leads to denial of service. The attack is possible to be carried out remotely. The exploit has been disclosed to the public and may 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 (2026-05-08)

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/open5gs/open5gs/issues/4433 referenced PoC, tagged "exploit" by a source, unverified
vuldb.com https://vuldb.com/submit/808422 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
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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/4433
exploit, issue-tracking
vuldb.com /submit/808422
third-party-advisory, exploit, vdb-entry
vuldb.com /vuln/361908
vdb-entry, technical-description, third-party-advisory
vuldb.com /vuln/361908/cti
signature, permissions-required, vdb-entry
vuldb.com /submit/808424
third-party-advisory, vdb-entry
github.com /open5gs/open5gs/
product

Sources

CVE List CVE-2026-8121
NVD CVE-2026-8121

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