CVE-2026-74391: Linux kernel · tracing: Bound synthetic-field strings with seq_buf
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 7.0.0-1014.14~24.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1014.14~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +11
Exploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 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-hwe-edge kernel versions. The vendor advisory confirms that this issue has been resolved. Users should update to the fixed kernel versions to mitigate this vulnerability.
Description
A vulnerability in the Linux kernel tracing subsystem was resolved by bounding synthetic-field strings with seq_buf to prevent buffer overflows. The issue involved unbounded string concatenation using strcat() on fixed-size buffers, which could lead to buffer overruns when handling long key lists, field names, or saved filters. The fix uses seq_buf to build strings safely and returns an error if limits are exceeded. This vulnerability affects specific versions of the linux-hwe-edge kernel and has been patched.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74391 (opens in a new tab)
- git.kernel.org/stable/c/0c584c27f6649a93ec12061cc779a4bd8f7c1434 (opens in a new tab)
- git.kernel.org/stable/c/88b901fdc1662b131ff908cbd017333b61e7acc8 (opens in a new tab)
- git.kernel.org/stable/c/baa333b2700a7fa3529d504529c8c10060fd687c (opens in a new tab)
- git.kernel.org/stable/c/cf334620036ad2250e008c7e7bb6646a3938b7b0 (opens in a new tab)
- git.kernel.org/stable/c/f07883450eb14d1cf020b55d9f3a7ec5683bcd26 (opens in a new tab)
- ubuntu.com/security/CVE-2026-74391 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74391 (opens in a new tab)
- git.kernel.org/linus/f07883450eb14d1cf020b55d9f3a7ec5683bcd26 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)