CVE-2026-86104: Fireware OS Resource Exhaustion in Login Process Allows Denial of Service
Analyzed
Published 29-09-2026Last modified 30-09-2026
Vulnerability summary
CVE-2026-86104 is a high (CVSS 8.7) Uncontrolled Resource Consumption vulnerability in watchguard fireware. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.7% of scored vulnerabilities.
CVSS score
8.7/10
010
High · v4.0 (CVE.org)EPSS score
0.36%
0%100%
Low · Change unavailableKEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded
Timeline
- 29-09-2026PublishedVulnerability first disclosed.
- 30-09-2026Last modifiedVulnerability information updated.
Description
An uncontrolled resource consumption vulnerability in the Fireware OS login process (wgagent) allows a remote, unauthenticated attacker to cause a denial of service by sending a specially crafted request.
CVSS metrics
3 scores · 2 sources · 2 versionsHigh 8.7Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NSourcesAll 2 agree
- NVDNIST8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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
High 7.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSourcesSingle source
EPSS trend
Probability
0.36%
Chance of exploitation in the next 30 days
Percentile
29%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
30-09-202622-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
- CWE-409Improper Handling of Highly Compressed Data (Data Amplification)The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.
- CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Affected systems
Watchguard2 products
- fireware≥ 12.0, < 12.5.21 | ≥ 12.12, < 12.12.3 | ≥ 2025.0, < 2026.2.3 | ≥ 2026.3, < 2026.3.2
- fireware os≥ 2026.3, < 2026.3.2 | ≥ 2025.0, < 2026.2.3 | ≥ 12.0, < 12.12.3 | ≥ 12.0, < 12.5.21
1 vendor · 2 products