CVE-2026-2525VulnerabilityPublished 16 Feb 2026Updated 23 Feb 2026

CVE-2026-2525: Free5GC · Denial of Service

Affects Free5GCSource 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: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 16 Feb 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
Free5GC	Affected =4.0 =4.1.0	Fixed in–

CPE configurations (1)

cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*

AI-suggested

1. Apply patches or updates from Free5GC maintainers as soon as they become available to address the vulnerability in the PFCP UDP Endpoint component. 2. Implement network-level filtering to restrict access to PFCP UDP ports (typically UDP port 8805) only to trusted and authenticated network elements, minimizing exposure to untrusted sources. 3. Deploy intrusion detection and prevention systems (IDS/IPS) with signatures or heuristics to detect anomalous or malformed PFCP packets indicative of exploitation attempts. 4. Use network segmentation to isolate 5G core network components from general enterprise or internet-facing networks, reducing attack surface. 5. Monitor system logs and network traffic for unusual PFCP activity or service crashes to enable rapid detection and response. 6. Conduct regular security assessments and penetration testing focused on 5G core network protocols and components. 7. Establish incident response plans specific to 5G network disruptions to minimize downtime and coordinate remediation. 8. Engage with Free5GC community and vendors for timely threat intelligence and updates related to this vulnerability. 9. Consider deploying redundancy and failover mechanisms in 5G core network architecture to maintain service continuity in case of DoS events. 10. Educate network operations teams about the risks associated with PFCP protocol exploitation and best practices for securing 5G core infrastructure.

Description

A vulnerability has been found in Free5GC up to 4.1.0. This affects an unknown function of the component PFCP UDP Endpoint. Such manipulation leads to denial of service. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.

Impact

The primary impact of CVE-2026-2525 is the disruption of 5G core network services due to denial of service conditions triggered by malicious PFCP UDP packets. This can lead to unavailability of critical 5G network functions such as session management, user plane control, and mobility management, potentially affecting end-user connectivity and service quality. For telecom operators and service providers, this could result in network outages, degraded user experience, and financial losses. Additionally, denial of service in the core network may cascade to impact dependent services and applications relying on 5G connectivity, including IoT deployments, emergency services, and enterprise communications. The remote and unauthenticated nature of the exploit increases the risk of widespread attacks, especially if threat actors automate exploitation attempts. While confidentiality and integrity are not directly impacted, the availability disruption alone can have severe operational consequences. Organizations using Free5GC in production or testing environments must consider the risk of service interruptions and potential reputational damage. The vulnerability also underscores the need for robust network segmentation and monitoring to detect and mitigate anomalous traffic targeting control plane protocols.

References

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