CVE-2026-33904 | Ella Core has a Denial of Service via SCTP connection cleanup deadlock

Ella Core is a 5G core designed for private networks. Prior to version 1.7.0, a deadlock in the AMF's SCTP notification handler causes the entire AMF control plane to hang until the process is restarted. An attacker with access to the N2 interface can cause Ella Core to hang, resulting in a denial of service for all subscribers. Version 1.7.0 adds deferred Radio cleanup in serveConn SCTP server so that every connection exit path removes the radio. Remove the stale-entry scan from SCTP Notification handling.

Published: 2026-03-27 Last update: 2026-04-20 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-33904 is rated Low Risk (26.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-33904

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-28 0.01%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33904

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 3.6 [email protected]

Weakness enumeration for CVE-2026-33904

GitHub Security Advisory for CVE-2026-33904

GHSA-9h59-p45g-445h · Severity: medium · Ecosystem: go — Ella Core has a Denial of Service via SCTP connection cleanup deadlock

Affected software / configurations for CVE-2026-33904

Vendor Product Version Raw CPE
ellanetworks ella_core < 1.7.0 cpe:2.3:a:ellanetworks:ella_core:*:*:*:*:*:*:*:*

References for CVE-2026-33904

cvelogic Threat Intelligence