CVE-2022-26318
CVE-2022-26318 is a security flaw in WatchGuard Firebox and XTM Appliances. Attackers can run their own code on WatchGuard Firebox and XTM Appliances from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 25 Mar 2022.[1]
WatchGuard Firebox and XTM Appliances is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. WatchGuard has published a fix or advice.
Description
CISA calls it an arbitrary code execution in WatchGuard Firebox and XTM Appliances. In its words: “On WatchGuard Firebox and XTM appliances, an unauthenticated user can execute arbitrary code.”[1]
The CVE record adds: “On WatchGuard Firebox and XTM appliances, an unauthenticated user can execute arbitrary code, aka FBX-22786. This vulnerability impacts Fireware OS before 12.7.2_U2, 12.x before 12.1.3_U8, and 12.2.x through 12.5.x before 12.5.9_U2.”[2]
The underlying weakness is heap buffer overflow (CWE-122), in MITRE’s list of common software weaknesses.
It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; WatchGuard’s advisory has them[3]. CISA names the product as WatchGuard Firebox and XTM Appliances.
Most families won’t have WatchGuard Firebox and XTM Appliances; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 25 Mar 2022, 21 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 15 Apr 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 78%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
WatchGuard has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Check whether you use it.WatchGuard Firebox and XTM Appliances is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 15 Apr 2022 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 78%.[4] |
See also
Other WatchGuard flaws
- CVE-2025-14733, WatchGuard Firebox: out of bounds write ·
- CVE-2025-9242, WatchGuard Firebox: out-of-bounds write ·
- CVE-2022-23176, WatchGuard Firebox and XTM: privilege escalation ·
Other heap buffer overflow flaws
- CVE-2026-94127, F5 BIG-IP APM: heap-based buffer overflow ·
- CVE-2025-25249, Fortinet products: heap-based buffer overflow ·
- CVE-2026-85880, Microsoft Windows: heap-based buffer overflow ·
- CVE-2025-32706, Microsoft Windows: common log file system (CLFS) driver heap-based buffer overflow ·
- CVE-2025-24993, Microsoft Windows: NTFS heap-based buffer overflow ·
Added the same day
- CVE-2022-26143, Mitel MiCollab, MiVoice Business Express: access control ·
- CVE-2022-21999, Microsoft Windows: print spooler privilege escalation ·
- CVE-2021-42237, Sitecore XP: remote command execution ·
- CVE-2021-22941, Citrix ShareFile: improper access control ·
- CVE-2020-9377, D-Link DIR-610 Devices: remote command execution ·
Every WatchGuard flaw on CISA’s list · Everything added in March 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “WatchGuard Firebox and XTM Appliances Arbitrary Code Execution”. Known Exploited Vulnerabilities Catalog, added 25 Mar 2022.
- ^ National Institute of Standards and Technology. “CVE-2022-26318 Detail”. National Vulnerability Database, published 4 Mar 2022.
- ^ WatchGuard. Advisories and fixes: watchguard.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.782, percentile 99.6, 31 Oct 2026.
- CVE Program. “CVE-2022-26318”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.