CVE-2025-36557Network attack vector

Service interruption via unchecked HTTP buffer copy

Published May 7, 2025 · Updated May 19, 2025

Denial of service in F5 BIG-IP products allows remote attackers to terminate TMM via requests to an RFC-enforcing virtual server. F5 maps the defect to an unchecked buffer copy but has not disclosed the crafted request structure or affected TMM code path. Reachability requires an HTTP profile with Enforce RFC Compliance on a virtual server; successful requests terminate TMM and interrupt traffic processing.

CVSS severity8.7
High
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in F5 BIG-IP products allows remote attackers to terminate TMM via requests to an RFC-enforcing virtual server. F5 maps the defect to an unchecked buffer copy but has not disclosed the crafted request structure or affected TMM code path. Reachability requires an HTTP profile with Enforce RFC Compliance on a virtual server; successful requests terminate TMM and interrupt traffic processing.

The record

CVE
CVE-2025-36557
Published
May 7, 2025
Updated
May 19, 2025
Vendor
F5 Networks
Product
BIG-IP
Classifications
CWE-120, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 7, 2025CVE publishedPublication date reported by the CVE source.
  2. May 19, 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 <16.1.5
  2. Affected versionversion=17.1.0 <17.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

F5 Networks · BIG-IPversion=16.1.0 <16.1.5; version=17.1.0 <17.1.2
F5 Networks · BIG-IP Next CNFversion=1.1.0 <1.4.0
F5 Networks · BIG-IP Next SPKversion=1.7.0 <1.7.9; version=1.8.0 <2.0.0

Published CVSS scores

8.7F5CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L
7.5F5CVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1499.004Application 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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