CVE-2026-86133: Fireware OS Pre-Authentication Integer Underflow in iked Allows Remote Denial of Service
Vulnerability summary
CVE-2026-86133 is a high (CVSS 8.2) Integer Underflow (Wrap or Wraparound) vulnerability in watchguard fireware. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 26.9% of scored vulnerabilities.
Timeline
- 29-09-2026PublishedVulnerability first disclosed.
- 30-09-2026Last modifiedVulnerability information updated.
Description
An integer underflow vulnerability in the WatchGuard Fireware OS IKE daemon (iked) allows a remote attacker who has completed the initial IKEv2 handshake to crash the iked process by sending a specially crafted encrypted IKEv2 message, resulting in a denial of service.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST8.2HighCVSS:4.0/AV:N/AC:L/AT:P/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
EPSS trend
Probability
0.35%
Chance of exploitation in the next 30 days
Percentile
27%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
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-191Integer Underflow (Wrap or Wraparound)The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.
- CWE-1284Improper Validation of Specified Quantity in InputThe product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.
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