CVE-2025-65561Public exploitNetwork attack vector

UPF crash via unchecked Local SEID conversion

Published Dec 18, 2025 · Updated Dec 18, 2025

Improper input validation in free5GC 4.1.0 allows remote attackers to crash the UPF via a crafted PFCP Session Modification Request. LocalNode.Sess converts the request's uint64 Local SEID to int, subtracts one, checks only the upper bound, and indexes the session slice with the resulting negative value. Network access to the PFCP endpoint is sufficient in the reproduced setup, and the demonstrated consequence is a Go runtime panic that terminates the UPF process.

CVSS severity7.5
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in free5GC 4.1.0 allows remote attackers to crash the UPF via a crafted PFCP Session Modification Request. LocalNode.Sess converts the request's uint64 Local SEID to int, subtracts one, checks only the upper bound, and indexes the session slice with the resulting negative value. Network access to the PFCP endpoint is sufficient in the reproduced setup, and the demonstrated consequence is a Go runtime panic that terminates the UPF process.

The record

CVE
CVE-2025-65561
Published
Dec 18, 2025
Updated
Dec 18, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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