CVE-2025-40019: Linux kernel · crypto: essiv – Check ssize for decryption and in-place encryption
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.4.0-1154.164~18.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.4.0-1154.164~18.04.1, 5.4.0-1157.164~18.04.1, 5.4.0-1157.166~18.04.1 +92
Exploitation evidence
Disclosed: evidence found.
CVE published 24 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7990-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7990-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8014-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8016-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7990-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-4 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: crypto: essiv - Check ssize for decryption and in-place encryption Move the ssize check to the start in essiv_aead_crypt so that it's also checked for decryption and in-place encryption.
References
- ubuntu.com/security/CVE-2025-40019 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40019 (opens in a new tab)
- git.kernel.org/linus/6bb73db6948c2de23e407fe1b7ef94bf02b7529f (opens in a new tab)
- git.kernel.org/stable/c/248ff2797ff52a8cbf86507f9583437443bf7685 (opens in a new tab)
- git.kernel.org/stable/c/6bb73db6948c2de23e407fe1b7ef94bf02b7529f (opens in a new tab)
- git.kernel.org/stable/c/da7afb01ba05577ba3629f7f4824205550644986 (opens in a new tab)
- git.kernel.org/stable/c/dc4c854a5e7453c465fa73b153eba4ef2a240abe (opens in a new tab)
- git.kernel.org/stable/c/df58651968f82344a0ed2afdafd20ecfc55ff548 (opens in a new tab)
- git.kernel.org/stable/c/f37e7860dc5e94c70b4a3e38a5809181310ea9ac (opens in a new tab)
- ubuntu.com/security/notices/USN-7990-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7990-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8014-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8016-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7990-3 (opens in a new tab)