Cyber Resilience

CVE-2026-4988

MediumPublic PoC

Published: 27 March 2026

Published
27 March 2026
Modified
30 March 2026
KEV Added
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Patch
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CVSS Score v4 6.3 CVSS:4.0/AV:N/AC:H/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
EPSS Score 0.0010 27.6th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-4988 is a medium-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Open5Gs Open5Gs. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 27.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

A security flaw has been discovered in Open5GS 2.7.6. This issue affects the function smf_gx_cca_cb/smf_gy_cca_cb/smf_s6b of the component CCA Message Handler. The manipulation results in denial of service. The attack may be launched remotely. Attacks of this nature are highly…

more

complex. The exploitability is assessed as difficult. The exploit has been released to the public and may be used for attacks.

CWE(s)
CWE-404

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
Why these techniques?

Remote exploitation of public-facing 5G core component (SMF CCA handler) via published flaw enables application-layer DoS through resource mishandling (CWE-404).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

Affected Assets

open5gs
open5gs
2.7.6

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CP-5 Contingency Plan Update
addresses: CWE-404

Contingency plan updates incorporate proper resource shutdown and release steps, preventing attackers from leveraging incomplete cleanup during recovery scenarios.

SC-10 Network Disconnect
addresses: CWE-404

Mandates explicit shutdown of the network connection at session conclusion, directly addressing improper resource release.

SC-4 Information in Shared System Resources
addresses: CWE-404

Requires proper shutdown/release procedures that include overwriting or isolating data to block unintended transfer via reused system objects.

SI-17 Fail-safe Procedures
addresses: CWE-404

Procedures can mandate orderly shutdown or release of resources when failures occur, preventing improper resource handling after a fault.

References