Stack-based buffer overflow in Linux kernel - CVE-2026-74391
Published: August 15, 2026
Vulnerability identifier: #VU142727
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74391
CWE-ID: CWE-121
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a stack-based buffer overflow in synthetic field helpers in kernel/trace/trace_events_hist.c when constructing synthetic variable names and generated histogram commands from long key lists, field names, or saved filters. A local user can supply crafted tracing inputs to cause a denial of service.
The issue occurs in tracing functionality while building fixed-size MAX_FILTER_STR_VAL staging buffers.
Affected software
Linux kernel
Ubuntu
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
Ubuntu
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
How to mitigate CVE-2026-74391
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
External References
- https://git.kernel.org/stable/c/0c584c27f6649a93ec12061cc779a4bd8f7c1434
- https://git.kernel.org/stable/c/88b901fdc1662b131ff908cbd017333b61e7acc8
- https://git.kernel.org/stable/c/baa333b2700a7fa3529d504529c8c10060fd687c
- https://git.kernel.org/stable/c/cf334620036ad2250e008c7e7bb6646a3938b7b0
- https://git.kernel.org/stable/c/f07883450eb14d1cf020b55d9f3a7ec5683bcd26