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

Source: https://junglewise.ai/threats/cve-2026-42408-f5-big-ip-sensitive-information-disclosure-in-tmsh-command  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-13. Updated: 2026-06-23  
License: CC BY 4.0 with a link back

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](https://junglewise.ai/threats/technologies/big-ip-dns), [F5 Big-Ip Access Policy Manager](https://junglewise.ai/threats/technologies/big-ip-access-policy-manager), [F5 Big-Ip Advanced Firewall Manager](https://junglewise.ai/threats/technologies/big-ip-advanced-firewall-manager), [F5 Big-Ip Local Traffic Manager](https://junglewise.ai/threats/technologies/big-ip-local-traffic-manager). Vendors: [F5](https://junglewise.ai/threats/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](https://my.f5.com/manage/s/article/K000157981)

## Related threats

- [F5 BIG-IP Appliance mode restriction bypass via path traversal](https://junglewise.ai/threats/cve-2026-42930-f5-big-ip-appliance-mode-restriction-bypass-via-path-traversal)
- [F5 BIG-IP privilege escalation in iControl SOAP via SNMP configuration](https://junglewise.ai/threats/cve-2026-42924-f5-big-ip-privilege-escalation-in-icontrol-soap-via-snmp)
- [F5 BIG-IP DoS in TMM via Client SSL Dynamic Record Sizing](https://junglewise.ai/threats/cve-2026-42920-f5-big-ip-dos-in-tmm-via-client-ssl-dynamic-record-sizing)
- [F5 BIG-IP privilege escalation in multiple modules](https://junglewise.ai/threats/cve-2026-42919-f5-big-ip-privilege-escalation-in-multiple-modules)
- [F5 BIG-IP DoS via HTTP/2 iRule redirection](https://junglewise.ai/threats/cve-2026-42409-f5-big-ip-dos-via-http-2-irule-redirection)