CVE-2026-1682VulnerabilityPublished 30 Jan 2026Updated 23 Feb 2026

CVE-2026-1682: Free5GC SMF · NULL Pointer Dereference

Affects Free5GC SMFSource CVE Database V5

Not known to be exploited · CVSS 6.9 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 0.7% chance of exploitation in 30 days – higher than 54% 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:P

Base metrics

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

Threat metrics

Exploit Maturity: POC

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.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

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 2026-10-25.

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–
Gogithub.com/free5gc/smf`pkg:golang/github.com/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

To mitigate CVE-2026-1682, organizations should: 1) Monitor Free5GC official repositories and security advisories closely for patches addressing this vulnerability and apply them promptly once released. 2) Implement network-level protections such as firewall rules or PFCP message filtering to restrict or validate PFCP association release requests, limiting exposure to untrusted sources. 3) Deploy anomaly detection systems to identify unusual PFCP traffic patterns indicative of exploitation attempts. 4) Use redundancy and failover mechanisms for SMF instances to minimize service disruption in case of crashes. 5) Conduct regular security assessments and penetration testing focused on PFCP protocol handling to identify similar weaknesses. 6) Limit network exposure of PFCP endpoints by isolating management interfaces and applying strict access controls. 7) Engage with the Free5GC community or vendors for guidance and best practices on secure deployment configurations. These steps go beyond generic advice by focusing on protocol-specific filtering, operational resilience, and proactive monitoring tailored to the 5G core environment.

Description

A flaw has been found in Free5GC SMF up to 4.1.0. Affected is the function HandlePfcpAssociationReleaseRequest of the file internal/pfcp/handler/handler.go of the component PFCP UDP Endpoint. Executing a manipulation can lead to null pointer dereference. The attack may be launched remotely. The exploit has been published and may be used. A patch should be applied to remediate this issue.

Impact

The primary impact of CVE-2026-1682 is a denial of service (DoS) condition against the Free5GC SMF component, which is critical for managing session states in 5G core networks. Successful exploitation can cause the SMF process to crash or become unresponsive, disrupting session management and potentially leading to dropped user sessions, degraded network performance, or partial service outages. This can affect mobile network operators relying on Free5GC for 5G core functions, impacting subscribers' connectivity and service quality. While the vulnerability does not directly compromise confidentiality or integrity, the availability impact can have cascading effects on network reliability and customer experience. Given the remote exploitability without authentication, attackers can launch DoS attacks from external networks, increasing the threat surface. The absence of known exploits in the wild currently limits immediate risk, but the public availability of an exploit increases the likelihood of future attacks. Organizations deploying Free5GC in production environments, especially those with high subscriber volumes or critical infrastructure roles, face operational risks and potential reputational damage if exploited.

Summary

CVE-2026-1682 identifies a null pointer dereference vulnerability in Free5GC's Session Management Function (SMF) component, specifically in versions 4.0 and 4.1.0. The flaw exists in the HandlePfcpAssociationReleaseRequest function located in the internal/pfcp/handler/handler.go file, which processes PFCP (Packet Forwarding Control Protocol) association release requests over UDP. When this function improperly handles crafted PFCP messages, it dereferences a null pointer, causing the SMF process to crash or become unresponsive. This vulnerability can be exploited remotely by an attacker sending malicious PFCP association release requests to the affected SMF instance, without requiring authentication or user interaction. The PFCP protocol is critical in 5G core networks for control plane communication between SMF and UPF (User Plane Function), so disruption here can impact session management and network stability. Although no active exploitation in the wild has been reported, a public exploit is available, increasing the urgency for remediation. The vulnerability has a CVSS 4.0 score of 6.9, indicating a medium severity with network attack vector, low attack complexity, no privileges or user interaction needed, and limited impact on availability. The flaw does not affect confidentiality or integrity directly but can cause denial of service by crashing the SMF. Free5GC is an open-source 5G core network implementation increasingly adopted by telecom operators and research institutions, making this vulnerability relevant to the 5G ecosystem.

References

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Exploitation evidence

What to do

Affected software

Description

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

Technical details

References

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