CVE-2025-22225
CVE-2025-22225 is a security flaw in VMware ESXi, VMware’s hypervisor, which runs virtual machines in data centres. Attackers are using a flaw in VMware ESXi. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 4 Mar 2025, and says ransomware gangs have used it.[1]
VMware ESXi 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. Fixed in version ESXi80U3d-24585383, ESXi80U2d-24585300 and ESXi70U3s-24585291 of VMware ESXi.
Description
CISA calls it an arbitrary write in VMware ESXi. In its words: “VMware ESXi contains an arbitrary write vulnerability. Successful exploitation allows an attacker with privileges within the VMX process to trigger an arbitrary kernel write leading to an escape of the sandbox.”[1]
The underlying weakness is CWE-123, in MITRE’s list of common software weaknesses.[2]
It scores 8.2 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| VMware ESXi | ESXi80U3d-24585383 |
| VMware ESXi | ESXi80U2d-24585300 |
| VMware ESXi | ESXi70U3s-24585291 |
Most families won’t have VMware ESXi; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 4 Mar 2025, within a day of it being made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 25 Mar 2025 to fix it.[1] CISA says ransomware gangs have used it.
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 1%. That’s in the top 37% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
VMware has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”[1]
- Check whether you use it.VMware ESXi 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 (fixed in version ESXi80U3d-24585383, ESXi80U2d-24585300 and ESXi70U3s-24585291 of VMware ESXi), or not in use. CISA gave US government agencies until 25 Mar 2025 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 8.2.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[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 1%.[4] |
See also
Other VMware ESXi flaws
- CVE-2024-37085: authentication bypass ·
- CVE-2020-3992: openSLP use-after-free ·
Other VMware flaws
- CVE-2025-22226, VMware ESXi, Workstation, and Fusion: information disclosure ·
- CVE-2025-22224, VMware ESXi and Workstation: TOCTOU race condition ·
- CVE-2024-38813, VMware vCenter Server: privilege escalation ·
- CVE-2024-38812, VMware vCenter Server: heap-based buffer overflow ·
- CVE-2022-22948, VMware vCenter Server: incorrect default file permissions ·
Added the same day
- CVE-2025-22226, VMware ESXi, Workstation, and Fusion: information disclosure ·
- CVE-2025-22224, VMware ESXi and Workstation: TOCTOU race condition ·
- CVE-2024-50302, Linux Kernel: use of uninitialized resource ·
Every VMware flaw on CISA’s list · Everything added in March 2025
References
- ^ Cybersecurity and Infrastructure Security Agency. “VMware ESXi Arbitrary Write Vulnerability”. Known Exploited Vulnerabilities Catalog, added 4 Mar 2025.
- ^ National Institute of Standards and Technology. “CVE-2025-22225 Detail”. National Vulnerability Database, published 4 Mar 2025.
- ^ VMware. Advisories and fixes: support.broadcom.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.010, percentile 63.3, 31 Oct 2026.
- CVE Program. “CVE-2025-22225”. 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.