CVE-2026-19318: Fireware OS Pre-Authentication Stack Buffer Overflow in iked Allows Remote Code Execution
Deferred
Published 27-08-2026Last modified 03-09-2026
Vulnerability summary
CVE-2026-19318 is a critical (CVSS 9.3) Stack-based Buffer Overflow vulnerability in watchguard fireware os. EPSS estimates a 0.47% chance of exploitation in the next 30 days, higher than 39.7% of scored vulnerabilities.
CVSS score
9.3/10
010
Critical · v4.0 (CVE.org)EPSS score
0.47%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded
Timeline
- 27-08-2026PublishedVulnerability first disclosed.
- 03-09-2026Last modifiedVulnerability information updated.
Description
A stack-based buffer overflow vulnerability in the WatchGuard Fireware OS iked process allows a remote unauthenticated attacker to execute arbitrary code by sending specially crafted network traffic.
CVSS metrics
2 scores · 2 sources · 1 versionCritical 9.3Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NSourcesAll 2 agree
- NVDNIST9.3CriticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/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
EPSS trend
Probability
0.47%
Chance of exploitation in the next 30 days
Percentile
40%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.47% on 22-09-2026
22-09-202622-10-2026
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-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
- CWE-129Improper Validation of Array IndexThe product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.
- 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.
Affected systems
Watchguard1 product
- fireware os≥ 2025.0, < 2026.2.2 | ≥ 12.0, < 12.12.2 | ≥ 12.0, < 12.5.20 | ≥ 2026.3, < 2026.3.1
1 vendor · 1 product
References
1 links- psirt.watchguard.com/CVE-2026-19318Vendor Advisory