CVE-2026-42058: An authenticated attacker's undisclosed requests to BIG-IP iControl REST can lead to an information leak of BI

Routine

MEDIUM 4.3UPGRADEUPGRADEUPGRADE

CVE-2026-42058 is a medium-severity flaw (CVSS 4.3) affecting big-ip access policy manager, big-ip advanced firewall manager, big-ip advanced web application firewall. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An authenticated attacker's undisclosed requests to BIG-IP iControl REST can lead to an information leak of BIG-IP local user account names. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 92%)
CISA exploited list	No
Weakness	CWE-732
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-ip access policy manager UPGRADE

Affected: >= 17.1.0 and <= 17.1.3 · >= 17.5.0 and <= 17.5.1 · >= 16.1.0 and <= 16.1.6 · 21.0.0

Fixed in: newer than 17.5.1

Safe to downgrade to: a release before 16.1.0

1. Check installed version

apt-cache policy big-ip-access-policy-manager || rpm -q big-ip-access-policy-manager || big-ip-access-policy-manager --version

2. UPGRADE to newer than 17.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade big-ip-access-policy-manager

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade big-ip-access-policy-manager

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 16.1.0 (Debian / Ubuntu)

apt-cache madison big-ip-access-policy-manager sudo apt install big-ip-access-policy-manager=<VERSION_BEFORE_16.1.0> sudo apt-mark hold big-ip-access-policy-manager

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list big-ip-access-policy-manager sudo dnf downgrade big-ip-access-policy-manager-<VERSION_BEFORE_16.1.0> sudo dnf versionlock add big-ip-access-policy-manager

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.

f5 big-ip advanced firewall manager UPGRADE

Affected: >= 17.1.0 and <= 17.1.3 · >= 17.5.0 and <= 17.5.1 · >= 16.1.0 and <= 16.1.6 · 21.0.0

Fixed in: newer than 17.5.1

Safe to downgrade to: a release before 16.1.0

1. Check installed version

apt-cache policy big-ip-advanced-firewall-manager || rpm -q big-ip-advanced-firewall-manager || big-ip-advanced-firewall-manager --version

2. UPGRADE to newer than 17.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade big-ip-advanced-firewall-manager

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade big-ip-advanced-firewall-manager

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 16.1.0 (Debian / Ubuntu)

apt-cache madison big-ip-advanced-firewall-manager sudo apt install big-ip-advanced-firewall-manager=<VERSION_BEFORE_16.1.0> sudo apt-mark hold big-ip-advanced-firewall-manager

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list big-ip-advanced-firewall-manager sudo dnf downgrade big-ip-advanced-firewall-manager-<VERSION_BEFORE_16.1.0> sudo dnf versionlock add big-ip-advanced-firewall-manager

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.

f5 big-ip advanced web application firewall UPGRADE

Affected: >= 17.1.0 and <= 17.1.3 · >= 17.5.0 and <= 17.5.1 · >= 16.1.0 and <= 16.1.6 · 21.0.0

Fixed in: newer than 17.5.1

Safe to downgrade to: a release before 16.1.0

1. Check installed version

apt-cache policy big-ip-advanced-web-application-firewall || rpm -q big-ip-advanced-web-application-firewall || big-ip-advanced-web-application-firewall --version

2. UPGRADE to newer than 17.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade big-ip-advanced-web-application-firewall

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade big-ip-advanced-web-application-firewall

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 16.1.0 (Debian / Ubuntu)

apt-cache madison big-ip-advanced-web-application-firewall sudo apt install big-ip-advanced-web-application-firewall=<VERSION_BEFORE_16.1.0> sudo apt-mark hold big-ip-advanced-web-application-firewall

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list big-ip-advanced-web-application-firewall sudo dnf downgrade big-ip-advanced-web-application-firewall-<VERSION_BEFORE_16.1.0> sudo dnf versionlock add big-ip-advanced-web-application-firewall

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.

f5 big-ip analytics UPGRADE

Affected: >= 17.1.0 and <= 17.1.3 · >= 17.5.0 and <= 17.5.1 · >= 16.1.0 and <= 16.1.6 · 21.0.0

Fixed in: newer than 17.5.1

Safe to downgrade to: a release before 16.1.0

1. Check installed version

apt-cache policy big-ip-analytics || rpm -q big-ip-analytics || big-ip-analytics --version

2. UPGRADE to newer than 17.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade big-ip-analytics

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade big-ip-analytics

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 16.1.0 (Debian / Ubuntu)

apt-cache madison big-ip-analytics sudo apt install big-ip-analytics=<VERSION_BEFORE_16.1.0> sudo apt-mark hold big-ip-analytics

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list big-ip-analytics sudo dnf downgrade big-ip-analytics-<VERSION_BEFORE_16.1.0> sudo dnf versionlock add big-ip-analytics

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.

f5 big-ip application acceleration manager UPGRADE

Affected: >= 17.1.0 and <= 17.1.3 · >= 17.5.0 and <= 17.5.1 · >= 16.1.0 and <= 16.1.6 · 21.0.0

Fixed in: newer than 17.5.1

Safe to downgrade to: a release before 16.1.0

1. Check installed version

apt-cache policy big-ip-application-acceleration-manager || rpm -q big-ip-application-acceleration-manager || big-ip-application-acceleration-manager --version

2. UPGRADE to newer than 17.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade big-ip-application-acceleration-manager

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade big-ip-application-acceleration-manager

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 16.1.0 (Debian / Ubuntu)

apt-cache madison big-ip-application-acceleration-manager sudo apt install big-ip-application-acceleration-manager=<VERSION_BEFORE_16.1.0> sudo apt-mark hold big-ip-application-acceleration-manager

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list big-ip-application-acceleration-manager sudo dnf downgrade big-ip-application-acceleration-manager-<VERSION_BEFORE_16.1.0> sudo dnf versionlock add big-ip-application-acceleration-manager

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.

f5 big-ip application security manager UPGRADE

Affected: >= 17.1.0 and <= 17.1.3 · >= 17.5.0 and <= 17.5.1 · >= 16.1.0 and <= 16.1.6 · 21.0.0

Fixed in: newer than 17.5.1

Safe to downgrade to: a release before 16.1.0

1. Check installed version

apt-cache policy big-ip-application-security-manager || rpm -q big-ip-application-security-manager || big-ip-application-security-manager --version

2. UPGRADE to newer than 17.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade big-ip-application-security-manager

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade big-ip-application-security-manager

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 16.1.0 (Debian / Ubuntu)

apt-cache madison big-ip-application-security-manager sudo apt install big-ip-application-security-manager=<VERSION_BEFORE_16.1.0> sudo apt-mark hold big-ip-application-security-manager

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list big-ip-application-security-manager sudo dnf downgrade big-ip-application-security-manager-<VERSION_BEFORE_16.1.0> sudo dnf versionlock add big-ip-application-security-manager

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-2026-42058?

big-ip access policy manager: upgrade to newer than 17.5.1; big-ip advanced firewall manager: upgrade to newer than 17.5.1; big-ip advanced web application firewall: upgrade to newer than 17.5.1. Exact commands for each OS are on this page.

Is CVE-2026-42058 being exploited?

CVE-2026-42058 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-2026-42058 affect?

CVE-2026-42058 affects big-ip access policy manager, big-ip advanced firewall manager, big-ip advanced web application firewall. Severity is medium (CVSS 4.3). An authenticated attacker's undisclosed requests to BIG-IP iControl REST can lead to an information leak of BIG-IP local user account names. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

How urgent is CVE-2026-42058?

Priority 17/100. No elevated risk signals yet.

Software pages

F5 BIG-IP vulnerabilities

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References

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