CVE-2025-61951Network attack vector

Unauthenticated TMM crash via undisclosed DTLS traffic

Published Oct 15, 2025 · Updated Oct 15, 2025

Affected F5 BIG-IP releases allow remote attackers to crash TMM through an out-of-bounds read triggered by undisclosed DTLS traffic. F5 has not disclosed the traffic pattern or the TMM code path that reads beyond its intended buffer. The issue is reachable without authentication only when a DTLS 1.2 virtual server uses a certificate and key with SSL Sign Hash set to ANY and the DTLS 1.2 backend requires client authentication.

CVSS severity8.7
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Affected F5 BIG-IP releases allow remote attackers to crash TMM through an out-of-bounds read triggered by undisclosed DTLS traffic. F5 has not disclosed the traffic pattern or the TMM code path that reads beyond its intended buffer. The issue is reachable without authentication only when a DTLS 1.2 virtual server uses a certificate and key with SSL Sign Hash set to ANY and the DTLS 1.2 backend requires client authentication.

The record

CVE
CVE-2025-61951
Published
Oct 15, 2025
Updated
Oct 15, 2025
Vendor
F5 Networks
Product
BIG-IP
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.1.0 <16.1.6.1
  2. Affected versionversion=17.1.0 <17.1.3
  3. Affected versionversion=17.5.0 <17.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

F5 Networks · BIG-IPversion=16.1.0 <16.1.6.1; version=17.1.0 <17.1.3; version=17.5.0 <17.5.1

Published CVSS scores

8.7F5 NetworksCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L
7.5F5 NetworksCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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