CVE-2025-61951: F5 BIG-IP · Out-of-bounds Read
Affects F5 BIG-IPSource CVE Database V5
Not known to be exploited · CVSS 7.5 High.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 14% 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:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Oct 2025
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 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| F5 BIG-IP | Affected
| Fixed in– |
AI-suggested
1. Monitor F5's official security advisories for patches addressing CVE-2025-61951 and apply updates promptly once available. 2. Temporarily disable DTLS 1.2 virtual servers or the Server SSL profile configurations that use SSL Sign Hash set to ANY if feasible, especially in environments where client authentication is enabled on backend servers. 3. Restrict network access to BIG-IP management and DTLS service ports using firewall rules or access control lists (ACLs) to limit exposure to untrusted networks. 4. Implement network-level anomaly detection to identify and block malformed DTLS traffic that could trigger the vulnerability. 5. Conduct thorough configuration reviews to ensure that SSL profiles and DTLS settings align with security best practices and minimize unnecessary exposure. 6. Prepare incident response plans to quickly recover from potential TMM crashes, including automated service restarts and failover mechanisms. 7. Engage with F5 support for guidance on interim workarounds or advanced configuration options that may mitigate the risk until patches are released.
Description
Undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. This issue may occur when a Datagram Transport Layer Security (DTLS) 1.2 virtual server is enabled with a Server SSL profile that is configured with a certificate, key, and the SSL Sign Hash set to ANY, and the backend server is enabled with DTLS 1.2 and client authentication. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.