CVE-2026-25501

free5GC SMF crash (nil pointer dereference) on PFCP SessionReportRequest when ReportType.DLDR is set but DownlinkDataReport IE is missing

View on CVE.org

Published Feb 24, 2026 CVSS 4.0 · 6.6 Medium EPSS < 1% KEV · Not listed

Description

free5GC SMF provides Session Management Function for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, SMF panics due to nil pointer dereference and the SMF process terminates. This is triggered by a malformed PFCP SessionReportRequest on the SMF PFCP (UDP/8805) interface. No known upstream fix is available, but some workarounds are available. ACL/firewall the PFCP interface so only trusted UPF IPs can reach SMF (reduce spoofing/abuse surface); drop/inspect malformed PFCP SessionReportRequest messages at the network edge where feasible, and/or add recover() around PFCP handler dispatch to avoid whole-process termination (mitigation only).

Analysis

Technical impact

A malformed PFCP SessionReportRequest that sets ReportType.DLDR but omits the required DownlinkDataReport Information Element causes a nil pointer dereference in free5GC SMF, leading to a panic and the termination of the SMF process. This results in a denial of service for the SMF component and potentially disrupts the upstream negotiation and ongoing service sessions in the 5G core network.

Affected Systems

The vulnerability affects the free5gc SMF component, versions up to and including 1.4.1. The impact is limited to installations of this software that expose the PFCP interface on UDP port 8805 to external traffic.

Risk and Exploitability

The CVSS base score of 6.6 indicates moderate severity, while the EPSS score of less than 1% suggests a low likelihood of active exploitation at present. The vulnerability is not listed in the CISA KEV catalog. An attacker can exploit it by remotely sending a crafted PFCP SessionReportRequest message to the SMF PFCP interface; proper authentication or additional remote code execution is not required. The crash is deterministic once the malformed message is processed, exposing the SMF to repeated denial of service attacks.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

free5gc

smf

affected

Version	Status	Constraints
`<= 1.4.1`	affected	—

Configuration 1 [-]

cpe:2.3:a:free5gc:smf:*:*:*:*:*:go:*:*

No data.

Vendor Product Versions

Free5gc

Smf

Version	Status	Scheme	Platform
`[0,1.4.1]`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Configure the PFCP interface so that only trusted UPF IP addresses can reach SMF (e.g., via firewall ACL rules).
Drop or inspect malformed PFCP SessionReportRequest messages at the network edge where possible to prevent the bad payload from reaching SMF.
Wrap the PFCP handler dispatch code in a recover() block to catch panics and avoid full process termination.

Generated by OpenCVE AI on April 17, 2026 at 16:08 UTC.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.360% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://github.com/free5gc/free5gc/issues/805
https://github.com/free5gc/free5gc/security/advisories/GHSA-vq85-8f6p-g9q5

History

Feb 26, 2026 3:15 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Feb 25, 2026 4:30 PM Affected versions updated. Scoring metrics updated View changes

Type	Values Removed	Values Added
CPEs		cpe:2.3:a:free5gc:smf::::::go::*
Metrics		cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}`

Feb 24, 2026 10:00 AM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Free5gc Free5gc smf
Vendors & Products		Free5gc Free5gc smf

Feb 24, 2026 12:45 AM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		free5GC SMF provides Session Management Function for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, SMF panics due to nil pointer dereference and the SMF process terminates. This is triggered by a malformed PFCP SessionReportRequest on the SMF PFCP (UDP/8805) interface. No known upstream fix is available, but some workarounds are available. ACL/firewall the PFCP interface so only trusted UPF IPs can reach SMF (reduce spoofing/abuse surface); drop/inspect malformed PFCP SessionReportRequest messages at the network edge where feasible, and/or add recover() around PFCP handler dispatch to avoid whole-process termination (mitigation only).
Title		free5GC SMF crash (nil pointer dereference) on PFCP SessionReportRequest when ReportType.DLDR is set but DownlinkDataReport IE is missing
Weaknesses		CWE-476
References		https://github.com/free5gc/free5gc/issues/805 https://github.com/free5gc/free5gc/security/advisories/GHSA-vq85-8f6p-g9q5
Metrics		cvssV4_0 `{'score': 6.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U'}`