VulnerabilityPublished 13 Feb 2026

CVE-2025-70122: UPF component of free5GC · A Heap Buffer Overflow

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 15:59 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 33% 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 13 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 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

AI-suggested

To mitigate CVE-2025-70122, organizations should first monitor for updates or patches from the free5GC project and apply them promptly once available. In the absence of an official patch, operators should implement strict input validation and bounds checking on PFCP messages, particularly the Session Modification Requests, to ensure declared lengths do not exceed buffer capacities. Network-level protections such as filtering or rate limiting PFCP traffic from untrusted sources can reduce exposure. Deploying anomaly detection systems to identify malformed PFCP packets may help detect exploitation attempts early. Operators should also consider segmenting the 5G core network to limit the attack surface and restrict access to the UPF from external or less trusted networks. Regularly auditing and testing the UPF component with fuzzing tools targeting PFCP message parsing can uncover similar vulnerabilities proactively. Finally, maintaining comprehensive logging and alerting on UPF crashes or unusual PFCP traffic patterns will aid in rapid incident response.

Description

A heap buffer overflow vulnerability in the UPF component of free5GC v4.0.1 allows remote attackers to cause a denial of service via a crafted PFCP Session Modification Request. The issue occurs in the SDFFilterFields.UnmarshalBinary function (sdf-filter.go) when processing a declared length that exceeds the actual buffer capacity, leading to a runtime panic and UPF crash.

Impact

The primary impact of CVE-2025-70122 is a denial of service condition caused by crashing the UPF component in free5GC 5G core networks. The UPF is responsible for forwarding user plane traffic, so its unavailability can disrupt data sessions, degrade user experience, and potentially cause widespread service outages. Organizations relying on free5GC for 5G core infrastructure, including telecom operators and private network providers, may experience network instability and loss of connectivity for subscribers. This can affect critical services dependent on 5G connectivity, such as IoT deployments, industrial automation, and emergency communications. The vulnerability does not directly compromise confidentiality or integrity but severely impacts availability. Since the attack vector is network-based and requires no authentication or user interaction, exploitation can be automated and launched remotely, increasing the risk of large-scale disruption. The absence of known exploits in the wild currently limits immediate threat but does not reduce the urgency for mitigation. The vulnerability could be leveraged in targeted attacks against telecom infrastructure or by threat actors aiming to cause service outages in strategic regions. Overall, the impact is high due to the critical nature of the affected component and ease of exploitation.

CWE-122Heap-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #16
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
Pre-design: Use a language or compiler that performs automatic bounds checking.
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Forced Integer Overflow (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/free5gc/free5gc/issues/746 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 20 Feb 2026, 22:46 UTC

WeaknessesCWE-122

Technical details

References

Community reviews

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