Vulnerability in F5 Big-Ip
CVE-2026-41959
Incorrect permission assignment vulnerabilities exist in BIG-IP and BIG-IQ TMOS Shell (tmsh) network diagnostics commands and in BIG-IP iControl REST. These vulnerabilities may allow an authenticated attacker to view the network status of destination systems. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (18.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 18.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- F5 Big-Ip — versions 21.1.0, 21.0.0, 17.5.0
- F5 Big-Ip Access Policy Manager — versions 21.0.0
- F5 Big-Ip Advanced Firewall Manager — versions 21.0.0
- F5 Big-Ip Advanced Web Application Firewall — versions 21.0.0
- F5 Big-Ip Analytics — versions 21.0.0
- F5 Big-Ip Application Acceleration Manager — versions 21.0.0
- F5 Big-Ip Application Security Manager — versions 21.0.0
- F5 Big-Ip Application Visibility And Reporting — versions 21.0.0
- F5 Big-Ip Automation Toolchain — versions 21.0.0
- F5 Big-Ip Carrier-Grade Nat — versions 21.0.0
Weakness classification (CWE)
References
- my.f5.com/manage/s/article/K000161022 (vendor-advisory, Mitigation, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-41959?
- CVE-2026-41959 is a medium-severity vulnerability in F5 Big-Ip, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 6.5/10. Published 2026-05-13.
- How severe is CVE-2026-41959?
- Medium severity. CVSS v3 base score is 6.5 out of 10.