CVE-2026-20916: An authenticated iControl REST user with low privileges can create or modify arbitrary files through an undisc

Routine

HIGH 8.1DOWNGRADE

CVE-2026-20916 is a high-severity flaw (CVSS 8.1) affecting big-iq centralized management. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An authenticated iControl REST user with low privileges can create or modify arbitrary files through an undisclosed iControl REST endpoint on the BIG-IQ system. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 70%)
CISA exploited list	No
Weakness	CWE-22
Published	2026-05-13
Last modified	2026-10-26

Publisher (CNA): F5 Networks · Vendor: f5

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-13 16:16 UTCPublished CVE record published
2026-10-26 14:10 UTCUpdated Record last modified

f5 big-iq centralized management DOWNGRADE

Affected: 8.4.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.4.0

1. Check installed version

apt-cache policy big-iq-centralized-management || rpm -q big-iq-centralized-management || big-iq-centralized-management --version

2. No fixed release: DOWNGRADE to a release before 8.4.0 (Debian / Ubuntu)

apt-cache madison big-iq-centralized-management sudo apt install big-iq-centralized-management=<VERSION_BEFORE_8.4.0> sudo apt-mark hold big-iq-centralized-management

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list big-iq-centralized-management sudo dnf downgrade big-iq-centralized-management-<VERSION_BEFORE_8.4.0> sudo dnf versionlock add big-iq-centralized-management

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-20916?

big-iq centralized management: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-20916 being exploited?

CVE-2026-20916 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-20916 affect?

CVE-2026-20916 affects big-iq centralized management. Severity is high (CVSS 8.1). An authenticated iControl REST user with low privileges can create or modify arbitrary files through an undisclosed iControl REST endpoint on the BIG-IQ system. Note: Software versions which have reached End of Technical Support (EoTS) are

How urgent is CVE-2026-20916?

Priority 36/100. High severity

Software pages

F5 BIG-IP vulnerabilities

References

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