CVE-2026-1684VulnerabilityPublished 30 Jan 2026Updated 23 Feb 2026

CVE-2026-1684: Free5GC SMF · Denial of Service

Affects Free5GC SMFSource CVE Database V5

Not known to be exploited · CVSS 6.9 Medium.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 30 Jan 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 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
Free5GCSMF	Affected =4.0 =4.1.0	Fixed in–
GitHubfree5gc/smf`pkg:github/free5gc/smf`Other threats	Affected =4.0 =4.1.0	Fixed in–

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

AI-suggested

Organizations should monitor Free5GC project updates and apply security patches promptly once available to address CVE-2026-1684. In the interim, network administrators should restrict access to the PFCP UDP endpoint of the SMF by implementing strict firewall rules and network segmentation to limit exposure to untrusted networks. Deploying intrusion detection or prevention systems (IDS/IPS) with signatures or heuristics to detect anomalous PFCP traffic patterns can help identify and block exploitation attempts. Additionally, logging and monitoring PFCP traffic for unusual report patterns can provide early warning of attack attempts. Network operators should also consider rate limiting PFCP messages to reduce the risk of DoS from flooding attacks. Conducting regular security assessments and penetration testing on 5G core components can help identify similar vulnerabilities proactively. Finally, organizations should maintain an incident response plan tailored to 5G core network disruptions to minimize downtime and service impact.

Description

A vulnerability was found in Free5GC SMF up to 4.1.0. Affected by this issue is the function HandleReports of the file /internal/context/pfcp_reports.go of the component PFCP UDP Endpoint. The manipulation results in denial of service. The attack can be executed remotely. It is advisable to implement a patch to correct this issue.

Impact

The primary impact of CVE-2026-1684 is the disruption of the 5G core network’s Session Management Function, which is responsible for session establishment, modification, and release. A successful denial of service attack can degrade or halt 5G service availability, affecting end-user connectivity and potentially causing cascading failures in dependent network functions. For telecommunications providers and enterprises relying on Free5GC SMF, this can lead to service outages, customer dissatisfaction, and financial losses. Given the critical role of 5G networks in supporting IoT, critical infrastructure, and enterprise applications, prolonged or widespread DoS could have broader economic and operational consequences. Although no confidentiality or integrity impact is noted, availability degradation in core network components is a significant risk. The remote and unauthenticated nature of the exploit increases the threat surface, especially in environments where the SMF PFCP endpoint is exposed or insufficiently protected. However, the lack of known exploits in the wild and the medium severity rating suggest the threat is moderate but warrants timely mitigation.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 23 Feb 2026, 21:50 UTC

Technical details

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