CVE-2025-37838: Linux kernel · HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 4.4.0-1149.155 : patch Linux kernel soon.
Data as of 27 Oct 2026, 05:11 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.4.0-1149.155, 4.15.0-1194.209~14.04.1, 4.4.0-274.308~14.04.1 +106
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Apr 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-7594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7655-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7686-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7711-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and included in Linux kernel updates distributed by vendors such as Ubuntu. Users should apply the latest kernel updates and reboot their systems to ensure the fix is applied. Due to an ABI change in the kernel updates, recompilation and reinstallation of any third-party kernel modules are required. Follow vendor-specific update instructions carefully. No additional mitigation steps are indicated by the vendor advisory.
Description
A use-after-free vulnerability was identified and fixed in the Linux kernel's ssi_protocol driver due to a race condition during module removal. The flaw occurs when work is scheduled on a freed structure, leading to potential memory corruption. This vulnerability affects numerous Linux kernel versions prior to the fixed releases. The issue has been addressed by ensuring that scheduled work is canceled before cleanup proceeds. A patch is available and included in recent Linux kernel updates. Users are advised to update and reboot to apply the fix. The vulnerability has a CVSS score of 7.8, indicating high impact on confidentiality, integrity, and availability. No known exploits are reported in the wild. The vendor advisory confirms the fix and recommends standard system updates and recompilation of third-party kernel modules due to ABI changes.
References
- ubuntu.com/security/CVE-2025-37838 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-37838 (opens in a new tab)
- git.kernel.org/linus/e3f88665a78045fe35c7669d2926b8d97b892c11 (opens in a new tab)
- git.kernel.org/stable/c/4b4194c9a7a8f92db39e8e86c85f4fb12ebbec4f (opens in a new tab)
- git.kernel.org/stable/c/834e602d0cc7c743bfce734fad4a46cefc0f9ab1 (opens in a new tab)
- git.kernel.org/stable/c/ae5a6a0b425e8f76a9f0677e50796e494e89b088 (opens in a new tab)
- git.kernel.org/stable/c/e3f88665a78045fe35c7669d2926b8d97b892c11 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7655-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7686-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7711-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-2 (opens in a new tab)