Is CVE-2026-42408 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-42408 being exploited in the wild.

How severe is CVE-2026-42408?

Medium severity, with a CVSS score of 4.4, published 13 May 2026.

Which products and versions are affected?

F5 BIG-IP DNS 17.5.0 - 17.5.1, 16.1.0 - 16.1.6, All versions currently under support; F5 Big-Ip Access Policy Manager 17.5.0 - 17.5.1, 16.1.0 - 16.1.6; F5 Big-Ip Advanced Firewall Manager 17.5.0 - 17.5.1, 16.1.0 - 16.1.6; F5 Big-Ip Local Traffic Manager 17.5.0 - 17.5.1, 16.1.0 - 16.1.6.

Is there a fix for CVE-2026-42408?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-42408 attacked?

It is attacked with local access, in a network appliance.

Am I affected by CVE-2026-42408?

Check whether you run F5 BIG-IP DNS, F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-42408: F5 BIG-IP sensitive information disclosure in tmsh command

CVE-2026-42408 · Severity: medium · CVSS 4.4 · Published 2026-05-13

A vulnerability in F5 BIG-IP systems with DNS provisioned could allow a highly privileged user to access sensitive information they should not be able to see. This occurs through a specific administrative command-line tool used for system configuration. While the attacker must already have high-level access, this flaw could lead to the exposure of internal system secrets or configuration data.

Technologies: F5 BIG-IP DNS, F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager, F5 Big-Ip Local Traffic Manager. Vendors: F5.

Quick answers

Is CVE-2026-42408 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-42408 being exploited in the wild.
How severe is CVE-2026-42408?: Medium severity, with a CVSS score of 4.4, published 13 May 2026.
Which products and versions are affected?: F5 BIG-IP DNS 17.5.0 - 17.5.1, 16.1.0 - 16.1.6, All versions currently under support; F5 Big-Ip Access Policy Manager 17.5.0 - 17.5.1, 16.1.0 - 16.1.6; F5 Big-Ip Advanced Firewall Manager 17.5.0 - 17.5.1, 16.1.0 - 16.1.6; F5 Big-Ip Local Traffic Manager 17.5.0 - 17.5.1, 16.1.0 - 16.1.6.
Is there a fix for CVE-2026-42408?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-42408 attacked?: It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-42408?: Check whether you run F5 BIG-IP DNS, F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A cleartext storage of sensitive information vulnerability (CWE-312) exists in an undisclosed TMOS Shell (tmsh) command within F5 BIG-IP. The flaw is specifically present when BIG-IP DNS is provisioned. An authenticated attacker with high privileges can execute this command via a local attack vector to disclose sensitive system information. The vulnerability affects multiple BIG-IP modules including DNS, APM, AFM, and LTM across versions 16.1.x and 17.5.x. F5 has released security advisory K000157981 to address this issue; users are advised to consult the vendor for specific patch versions or mitigations.

Affected products

F5 BIG-IP DNS 17.5.0 - 17.5.1, 16.1.0 - 16.1.6
F5 BIG-IP Access Policy Manager 17.5.0 - 17.5.1, 16.1.0 - 16.1.6
F5 BIG-IP Advanced Firewall Manager 17.5.0 - 17.5.1, 16.1.0 - 16.1.6
F5 BIG-IP Local Traffic Manager 17.5.0 - 17.5.1, 16.1.0 - 16.1.6

Timeline

2026-05-13: advisory
2026-05-13: disclosed

References

https://my.f5.com/manage/s/article/K000157981

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