CVE-2025-40896: The server certificate was not verified when an Arc agent connected to a Guardian or CMC. A malicious actor

Q: How do I fix CVE-2025-40896?

arc: upgrade to 2.2.0. Exact commands for each OS are on this page.

Q: Is CVE-2025-40896 being exploited?

CVE-2025-40896 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-40896 affect?

CVE-2025-40896 affects arc. Severity is medium (CVSS 6.5). The server certificate was not verified when an Arc agent connected to a Guardian or CMC. A malicious actor could perform a man-in-the-middle attack and intercept the communication between the Arc agent and the Guardian or CMC. This coul

Q: How urgent is CVE-2025-40896?

Priority 28/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 6.5REMOTEUPGRADE

CVE-2025-40896 is a medium-severity flaw (CVSS 6.5) affecting arc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The server certificate was not verified when an Arc agent connected to a Guardian or CMC. A malicious actor could perform a man-in-the-middle attack and intercept the communication between the Arc agent and the Guardian or CMC. This could result in theft of the client token and sensitive information (such as assets and alerts), impersonation of the server, or injection of spoofed data (such as false asset information or vulnerabilities) into t

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.1% (top 99%)
CISA exploited list	No
Weakness	CWE-295
Published	2026-03-04
Last modified	2026-06-17

Publisher (CNA): Nozomi Networks Inc. · Vendor: nozominetworks

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-04 14:16 UTCPublished CVE record published
2026-06-17 09:22 UTCUpdated Record last modified

nozominetworks arc UPGRADE

Affected: < 2.2.0

Fixed in: 2.2.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy arc || rpm -q arc || arc --version

2. UPGRADE to 2.2.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade arc

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade arc

Note

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

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-2025-40896?

arc: upgrade to 2.2.0. Exact commands for each OS are on this page.

Is CVE-2025-40896 being exploited?

CVE-2025-40896 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-2025-40896 affect?

CVE-2025-40896 affects arc. Severity is medium (CVSS 6.5). The server certificate was not verified when an Arc agent connected to a Guardian or CMC. A malicious actor could perform a man-in-the-middle attack and intercept the communication between the Arc agent and the Guardian or CMC. This coul

How urgent is CVE-2025-40896?

Priority 28/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2024-52928 CRITICAL 9.6 UPGRADE Arc before 1.26.1 on Windows has a bypass issue in the site settings that allows websites (with previously gra

References

← Back to latest CVEs