VulnerabilityPublished 24 Mar 2026

CVE-2026-30653: free5gc · CVE-2026-30653 is a high-severity

Affects free5gcSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHubfree5gc/free5gc`pkg:github/free5gc/free5gc`Other threats	Affected <=4.2.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Monitor Free5GC project repositories and security advisories closely for official patches addressing CVE-2026-30653 and apply them promptly once available.
Until patches are released, implement network-level protections such as firewall rules or intrusion prevention systems (IPS) to restrict access to the AMF interface from untrusted sources.
Employ rate limiting and anomaly detection on authentication failure messages to detect and block suspicious traffic patterns that could trigger the vulnerability.
Conduct thorough testing of Free5GC deployments in controlled environments to identify abnormal behavior related to authentication failure handling.
Consider deploying redundant AMF instances and failover mechanisms to maintain service availability in case of an attack.
Engage with Free5GC community and vendors for guidance and potential workarounds.
Incorporate robust logging and monitoring to detect early signs of exploitation attempts.
Review and harden overall 5G core network security posture, including segmentation and access controls, to minimize attack surface exposure.

Description

CVE-2026-30653 is a high-severity vulnerability in Free5GC version 4.2.0 and earlier that allows a remote attacker to cause a denial of service (DoS) by exploiting the HandleAuthenticationFailure function in the AMF component. The flaw does not require authentication or user interaction and can be triggered remotely over the network. It impacts availability but does not affect confidentiality or integrity. No known exploits are currently reported in the wild. The vulnerability is classified under CWE-400, indicating a resource exhaustion issue. Organizations using Free5GC for 5G core network functions are at risk of service disruption. Mitigation involves applying patches once available or implementing network-level protections to limit exposure. Countries with significant 5G deployments using Free5GC are most likely to be affected.

Impact

The primary impact of CVE-2026-30653 is the disruption of 5G core network services due to denial of service conditions in the AMF component of Free5GC. This can lead to service outages affecting user authentication and mobility management, potentially causing widespread connectivity issues for subscribers relying on affected networks. Organizations operating 5G infrastructure with Free5GC may experience degraded network availability, impacting customer experience and possibly violating service level agreements. The vulnerability does not compromise data confidentiality or integrity but threatens network reliability and operational continuity. Given the critical nature of 5G networks for communications, emergency services, and IoT applications, such disruptions could have cascading effects on dependent services and industries. The ease of remote exploitation without authentication increases the risk of opportunistic attacks or targeted disruptions by malicious actors.

Summary

CVE-2026-30653 is a denial of service vulnerability identified in Free5GC, an open-source 5G core network implementation widely used for research, development, and some production environments. The vulnerability exists in the Authentication Management Function (AMF) component, specifically within the HandleAuthenticationFailure function. When this function processes certain malformed or malicious authentication failure messages, it can cause resource exhaustion or a crash, leading to denial of service. The vulnerability is remotely exploitable without any authentication or user interaction, making it accessible to unauthenticated attackers over the network. The CVSS v3.1 base score of 7.5 reflects the high impact on availability with no impact on confidentiality or integrity. The underlying issue corresponds to CWE-400, which relates to uncontrolled resource consumption. Although no public exploits are currently known, the potential for disruption in 5G core network operations is significant given the critical role of the AMF in managing authentication and mobility. The lack of patches at the time of disclosure necessitates proactive mitigation strategies. This vulnerability highlights the importance of robust input validation and resource management in telecom infrastructure software.

CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/free5gc/free5gc/issues/826 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 31 Mar 2026, 20:35 UTC

WeaknessesCWE-400

Technical details

References

Community reviews

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