CVE-2026-4315
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA Cross-Site Request Forgery (CSRF) vulnerability in the WatchGuard Fireware OS WebUI could allow a remote attacker to trigger a denial-of-service (DoS) condition in the Fireware Web UI by convincing an authenticated administrator into visiting a malicious web page.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA Cross-Site Request Forgery (CSRF) vulnerability in WatchGuard Fireware OS WebUI allows a remote attacker to trigger a denial-of-service condition by tricking an authenticated administrator into visiting a malicious web page. The attacker exploits the lack of CSRF protection in the WebUI to send crafted requests that cause the UI to become unavailable or unresponsive.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 2025.1, < 2026.2>= 12.5, < 12.5.18>= 11.8, < 11.12.4= 11.12.4>= 12.0, < 12.12CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm WatchGuard Fireware OS installationIdentify the WatchGuard appliance model and access the Fireware OS version through the WebUI status page, CLI command 'fw PrintVersion', or the management interface System > About pageAffected if The device is not running WatchGuard Fireware OS or the version is not in the affected range
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Verify WebUI is accessibleConfirm the Fireware WebUI management interface is enabled and reachable by attempting to access the HTTPS management portal or checking the WebUI service status via CLI with 'wg ssl vpn webui status'Affected if WebUI is disabled or not in use, as the vulnerability requires the WebUI to be accessible for the CSRF attack to be possible
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Check for CSRF token implementationInspect HTTP responses from the WebUI login and main pages by capturing traffic with a browser developer tool or proxy; examine forms and AJAX requests for the presence of anti-CSRF tokens or unique request identifiersAffected if Forms and state-changing requests lack CSRF tokens or unique request validation parameters
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Verify SameSite cookie attributesUse browser developer tools or a packet capture to examine cookies set by the Fireware WebUI during authentication; check if the session cookie includes the SameSite=Strict or SameSite=Lax attributeAffected if Session cookies are missing SameSite attributes or set with SameSite=None without secure flag, indicating lack of CSRF protection
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Test for CSRF vulnerabilityWith administrator authentication active, attempt to submit a state-changing request (such as a firewall rule modification or interface toggle) from an external origin using a crafted HTML page to see if the request executes without validationAffected if External-origin requests are processed without requiring anti-CSRF validation, confirming the vulnerability is present
The environment is affected if running a vulnerable WatchGuard Fireware OS version with WebUI enabled, and the WebUI lacks CSRF token validation and proper SameSite cookie attributes on session cookies.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped11.12.412.5.1812.12
Implement anti-CSRF tokens and SameSite cookie attributes in the Fireware WebUI to validate request authenticity. Administrators should avoid browsing untrusted sites while authenticated to the Fireware management interface.
Upgrade to Fireware OS 11.12.5+ (for 11.x users), 12.12+ (for 12.x users), or 2026.2+ (for 2025/2026 line users) - verify exact GA release at www.watchguard.com
- 1. Identify the currently installed Fireware OS version on the WatchGuard device via the WebUI or CLI (using 'fwmon --ver' or checking System > About in the WebUI)
- 2. Based on the installed major version line, upgrade to a version newer than the last affected release: For 11.x line, upgrade to version 11.12.5 or later build; For 12.x line, upgrade to version 12.12 or later; For 2025/2026 line, upgrade to version 2026.2 or later
- 3. Download the firmware from the WatchGuard portal (www.watchguard.com) ensuring it is the official signed release
- 4. Upload the firmware via the Fireware WebUI (System > Firmware) or via CLI using the 'fwupdate' command
- 5. After upgrade, verify the new version is installed and test that the WebUI is responsive
- 6. As a CSRF mitigation, administrators should not browse untrusted sites while authenticated to the Fireware WebUI and should use separate browser sessions
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation16.0 h
- Testing8.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-4315 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-4315 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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