CyberSecBulletin
CVE-2025-53856NVD status: Analyzed

BIG-IP: Incorrect Control Flow Scoping

Published Updated By the CyberSecBulletin desk

CVE-2025-53856 is a high-severity incorrect control flow scoping vulnerability in BIG-IP from F5, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 17.5.1.3, 17.1.3, 16.1.6.1 as the first without the flaw, so updating BIG-IP to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update BIG-IP to 17.5.1.3 or 17.1.3 or 16.1.6.1 or 15.1.10.8, whichever matches your release line, or a later version.
  2. Update Big-ip Access Policy Manager to 15.1.10.8 or 16.1.6.1 or 17.1.3, whichever matches your release line, or a later version.
  3. Update Big-ip Advanced Firewall Manager to 15.1.10.8 or 16.1.6.1 or 17.1.3, whichever matches your release line, or a later version.
  4. Read the advisory on my.f5.com for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
F5BIG-IP17.5.0 up to, but not including, 17.5.1.3; 17.1.0 up to, but not including, 17.1.3; 16.1.0 up to, but not including, 16.1.6.1; 15.1.0 up to, but not including, 15.1.10.817.5.1.3, 17.1.3, 16.1.6.1, 15.1.10.8
F5Big-ip Access Policy Manager15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Advanced Firewall Manager15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Advanced Web Application Firewall15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Analytics15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Application Acceleration Manager15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Application Security Manager15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Application Visibility And Reporting15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Automation Toolchain15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Carrier-grade Nat15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Container Ingress Services15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Ddos Hybrid Defender15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Domain Name System15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Edge Gateway15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Fraud Protection Service15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Global Traffic Manager15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.315.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Link Controller15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Local Traffic Manager15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Policy Enforcement Manager15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip SSL Orchestrator15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Webaccelerator15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3
F5Big-ip Websafe15.1.0 up to, but not including, 15.1.10.8; 16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.0 through 17.5.115.1.10.8, 16.1.6.1, 17.1.3

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (f5.com).

Scoring systemScoreSeverityScored by
CVSS 4.08.7HighCNA (f5.com)
CVSS 3.17.5HighCNA (f5.com)

Official description

When a virtual server, network address translation (NAT) object, or secure network address translation (SNAT) object uses the embedded Packet Velocity Acceleration (ePVA) feature, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. To determine which BIG-IP platforms have an ePVA chip refer to K12837: Overview of the ePVA feature https://my.f5.com/manage/s/article/K12837 . Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Control Flow Scoping

The product does not properly return control flow to the proper location after it has completed a task or detected an unusual condition.

More Incorrect Control Flow Scoping vulnerabilities (CWE-705)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in BIG-IP

All BIG-IP vulnerabilities

Spotted an error? Tell us.