CVE-2026-64004: Linux kernel · net/iucv: fix locking in .getsockopt
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +66
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 19 Jul 2026
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.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 should be applied to affected Linux kernel versions to fix the locking issue causing the race condition. Users should update to the fixed kernel versions at or beyond 7.0.0-28.28~24.04.1 or the corresponding patched releases. No additional mitigation is indicated by the vendor advisory.
Description
A race condition vulnerability in the Linux kernel's net/iucv subsystem allowed local AF_IUCV HIPER users to cause a kernel crash via a NULL pointer dereference triggered by concurrent recvmsg() and getsockopt(SO_MSGSIZE) calls. The issue was fixed by improving locking in the affected code. Multiple Linux kernel versions prior to 7.0.0-28.28~24.04.1 and related versions are affected. A patch is available and should be applied to prevent potential system crashes.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64004 (opens in a new tab)
- git.kernel.org/stable/c/1fc30bd4e55e2dd622d2d366cecd732c1841bbee (opens in a new tab)
- git.kernel.org/stable/c/3589d20a666caf30ad100c960a2de7de390fce88 (opens in a new tab)
- git.kernel.org/stable/c/45bb8de8c95d8899f4b8f61bd9bceb8132af73cb (opens in a new tab)
- git.kernel.org/stable/c/69554adc7a6fa04ede3ad7512321d83748e3c920 (opens in a new tab)
- git.kernel.org/stable/c/6e792b8dd3002bbc4136745928a9605df1a72b8a (opens in a new tab)
- git.kernel.org/stable/c/884eb247b74d86db97e3a37f0d6fc8e1e83590dd (opens in a new tab)
- git.kernel.org/stable/c/9817369243380e287ebe5525411557eaa3aa2a79 (opens in a new tab)
- git.kernel.org/stable/c/cd691beafea0dd779e69e81ccc26b0ab50efcb5e (opens in a new tab)
- ubuntu.com/security/CVE-2026-64004 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64004 (opens in a new tab)
- git.kernel.org/linus/3589d20a666caf30ad100c960a2de7de390fce88 (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8903-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8905-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8906-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8904-1 (opens in a new tab)