WatchGuard Firebox Insecure Deserialization in Fireware Access Portal
An Insecure Deserialization vulnerability in WatchGuard Fireware OS allows an attacker that has obtained write access to the local filesystem through another vulnerability to execute arbitrary code in the context of the portald user. Note, this vulnerability does not affect Firebox platforms that do not support the Access Portal feature, including the T15 and T35.
- Published
- Mar 30, 2026
- Updated
- Aug 27, 2026
- EPSS
- 0.4% · 31th percentile
- CWE
- CWE-502
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Report tools
Action score
33
Monitor
Low priority for now.
- CVSS
- 33 / 40 · 8.4 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · WatchGuard
- 8.4
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| watchguard | fireware | cpe:2.3:o:watchguard:fireware |
| watchguard | firebox m295 | cpe:2.3:h:watchguard:firebox_m295 |
| watchguard | firebox m395 | cpe:2.3:h:watchguard:firebox_m395 |
| watchguard | firebox m495 | cpe:2.3:h:watchguard:firebox_m495 |
| watchguard | firebox m595 | cpe:2.3:h:watchguard:firebox_m595 |
| watchguard | firebox m695 | cpe:2.3:h:watchguard:firebox_m695 |
| watchguard | firebox t115-w | cpe:2.3:h:watchguard:firebox_t115-w |
| watchguard | firebox t125 | cpe:2.3:h:watchguard:firebox_t125 |
| watchguard | firebox t125-w | cpe:2.3:h:watchguard:firebox_t125-w |
| watchguard | firebox t145 | cpe:2.3:h:watchguard:firebox_t145 |
| watchguard | firebox t145-w | cpe:2.3:h:watchguard:firebox_t145-w |
| watchguard | firebox t185 | cpe:2.3:h:watchguard:firebox_t185 |
and 25 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- watchguard fireware2025.1 and later · before 2026.2
- watchguard fireware12.1 and later · before 12.12
Versions reported by the vendor
Affected version ranges reported by the assigning authority (WatchGuard). Independent of NVD's CPE analysis and usually ahead of it.
WatchGuard Fireware OS
- 2025.1 and later · before 2026.2affected
- 12.1 and later · before 12.12affected
- 12.1 and later · before 12.11.9affected
Same product
watchguard: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-9242WatchGuard Firebox iked Out of Bounds Write VulnerabilityKEV94Now
- CVE-2022-26318On WatchGuard Firebox and XTM appliances, an unauthenticated user can execute arbitrary code, aka FBX-22786.KEV92Now
- CVE-2025-14733WatchGuard Firebox iked Out of Bounds Write VulnerabilityKEV75This week
- CVE-2022-23176WatchGuard Firebox and XTM appliances allow a remote attacker with unprivileged credentials to access the system with a privileged managemenKEV68This week
- CVE-2013-6021Buffer overflow in WGagent in WatchGuard WSM and Fireware before 11.8 allows remote attackers to execute arbitrary code via a long sessionid41Plan
- CVE-2022-31789An integer overflow in WatchGuard Firebox and XTM appliances allows an unauthenticated remote attacker to trigger a buffer overflow and pote40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- btaolfinder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-1337194 days apartWatchGuard Firebox Management Web UI Denial of Service via Unsafe Deserialization27Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- Administrator privileges are required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-502 · Deserialization of Untrusted DataCVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Root cause
Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.
The bug in code
The whole CWE-502 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
payload = sock.recv(65536)job = pickle.loads(payload)Fixed
payload = sock.recv(65536)if not hmac.compare_digest(sign(payload), header_sig): raise PermissionError("invalid signature")job = JobSchema.validate(json.loads(payload))Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.