CVE-2024-40711
CVE-2024-40711 is a security flaw in Veeam Backup & Replication, backup software companies use. Attackers can run their own code on Veeam Backup & Replication 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 17 Oct 2024, and says ransomware gangs have used it.[1]
Veeam Backup & Replication 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. Veeam has published a fix or advice.
Description
CISA calls it a backup and replication deserialization in Veeam Backup & Replication. In its words: “Veeam Backup and Replication contains a deserialization vulnerability allowing an unauthenticated user to perform remote code execution.”[1]
The underlying weakness is deserialization of untrusted data (CWE-502), in MITRE’s list of common software weaknesses.[2]
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; Veeam’s advisory has them[3]. CISA names the product as Veeam Backup & Replication.
Most families won’t have Veeam Backup & Replication; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 17 Oct 2024, 40 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 7 Nov 2024 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 90%. 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
Veeam has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.”[1]
- Check whether you use it.Veeam Backup & Replication 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 7 Nov 2024 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, 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 90%.[4] |
See also
Other Veeam Backup & Replication flaws
- CVE-2023-27532: cloud connect missing authentication for critical function ·
- CVE-2022-26501: remote code execution ·
- CVE-2022-26500: remote code execution ·
Other deserialization of untrusted data flaws
- CVE-2021-23758, Ajax.NET Professional: deserialization of untrusted data ·
- CVE-2026-63077, JetBrains TeamCity: deserialization of untrusted data ·
- CVE-2026-50522, Microsoft SharePoint: deserialization of untrusted data ·
- CVE-2026-58644, Microsoft SharePoint: deserialization of untrusted data ·
- CVE-2026-45659, Microsoft SharePoint Server: deserialization of untrusted data ·
Every Veeam flaw on CISA’s list · Everything added in October 2024
References
- ^ Cybersecurity and Infrastructure Security Agency. “Veeam Backup and Replication Deserialization Vulnerability”. Known Exploited Vulnerabilities Catalog, added 17 Oct 2024.
- ^ National Institute of Standards and Technology. “CVE-2024-40711 Detail”. National Vulnerability Database, published 7 Sep 2024.
- ^ Veeam. Advisories and fixes: veeam.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.904, percentile 99.8, 31 Oct 2026.
- CVE Program. “CVE-2024-40711”. 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.