High severity · published Sep 29, 2026
CVE-2026-13046
Fireware OS Deserialization of Untrusted Data in samld Allows Remote Code Execution
7.2
CVSS
0.4%
EPSS
No
On KEV
Description
A deserialization of untrusted data vulnerability in WatchGuard Fireware OS's SAML single sign-on session handling (samld) allows an attacker who has already obtained the ability to write files on the appliance to execute arbitrary code in the context of the samld service by causing samld to load a maliciously crafted session file.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FO
Fireware OS · WatchGuard
2026.3 before 2026.3.2; 2025.0 before 2026.2.3; 12.0 before 12.12.3; 12.11 before 12.11.10 · source: vendor
FI
Fireware · Watchguard
12.0 before 12.11.10; 12.12 before 12.12.3; 2025.0 before 2026.2.3; 2026.3 before 2026.3.2 · source: NVD
In the news
VulnerabilityHigh
ZDI-26-749: WatchGuard FireWare OS samld SAMLSession Deserialization of Untrusted Data Remote Code Execution Vulnerability
This vulnerability allows remote attackers to execute arbitrary code on affected installations of WatchGuard FireWare OS. An attacker must first obtain the ability to write to the samld session directory on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.5. The following CVEs are assigned: CVE-2026-13046.
Sep 30, 2026·Zero Day Initiative
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-13046
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-13046
vendor-advisory
https://psirt.watchguard.com/CVE-2026-13046
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