CVE-2025-6999
MediumCVSS 6.9Exploitation Probability (EPSS)
Low risk41th percentile - higher than 41% of all known CVEs
Summary
An HTTP Request Smuggling vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to bypass request parameter sanitization and perform a reflected self-XSS attack. WatchGuard believes there is no practical exploit chain with meaningful security impact.
Risk Assessment
The risk to the organization is limited as the vendor does not confirm practical exploitation, but the vulnerability could enable XSS attacks on portal users.
Recommendation
Monitor WatchGuard updates and apply patches when available. Restrict access to the authentication portal to trusted networks only.
Other vulnerabilities in WatchGuard Fireware OS
See all- CVE-2026-93866Critical
An integer overflow vulnerability exists in the WebSocket connection handling used by WatchGuard Fireware OS's Access Portal. A remote, unauthenticated attacker can write beyond the bounds of a heap buffer by sending a specially crafted request while the Access Portal feature is enabled.
- CVE-2026-93865Critical
A missing authentication vulnerability exists in the Fireware OS FireCluster synchronization daemon. A remote, unauthenticated attacker can invoke privileged system-level administrative actions by sending a specially crafted request to the FireCluster management IP when the clustering feature is enabled.
- CVE-2026-93857Critical
A stack-based buffer overflow vulnerability exists in Fireware OS's SIP proxy. A remote, unauthenticated attacker can execute arbitrary code by sending a specially crafted request through a policy that uses the SIP proxy.
- CVE-2026-90465Critical
A missing authentication vulnerability exists in FireCluster Sync processing. An attacker positioned on the cluster interconnect, such as a compromised cluster peer or an on-path network attacker, can invoke privileged firewall management actions as root by sending a specially crafted request.
- CVE-2026-112710Critical
A heap-based buffer overflow vulnerability exists in the Fireware OS authentication service. An attacker who controls or intercepts traffic to the configured Active Directory server can create a denial of service condition and potentially execute arbitrary code by returning a specially crafted response.
- CVE-2026-112709Critical
A heap-based buffer overflow vulnerability exists in the Fireware OS authentication service. An attacker who controls or intercepts traffic to the configured Active Directory server can create a denial of service condition and potentially execute arbitrary code by returning a specially crafted response.
- CVE-2026-103594Critical
A stack-based buffer overflow vulnerability exists in Fireware OS's WireGuard configuration processing. A remote attacker with man-in-the-middle TLS-decrypted access between the Firebox and WatchGuard Cloud can create a denial of service condition and potentially execute arbitrary code by tampering with a FireCloud Gateway configuration payload.
- CVE-2026-86131Critical
A code injection vulnerability in WatchGuard Fireware OS's BOVPN Over TLS client configuration handling allows an attacker who controls the remote VPN server to execute arbitrary commands as root on the connecting Firebox.
- CVE-2026-19318Critical
A stack-based buffer overflow in the iked process of WatchGuard Fireware OS allows a remote unauthenticated attacker to execute arbitrary code by sending specially crafted network traffic.
- CVE-2026-19315Critical
A type confusion vulnerability in the iked process of WatchGuard Fireware OS allows a remote unauthenticated attacker to execute arbitrary code by sending specially crafted network traffic.
Original NVD description (English source)
An HTTP Request Smuggling [CWE-444] vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to evade request parameter sanitation and perform a reflected self-Cross-Site Scripting (XSS) attack. WatchGuard does not believe there is a practical exploit chain with a meaningful security impact for this vulnerability.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

