CVE-2026-43197: Linux Kernel out-of-bounds read (CVSS 9.1)

Description

In the Linux kernel, the following vulnerability has been resolved: netconsole: avoid OOB reads, msg is not nul-terminated msg passed to netconsole from the console subsystem is not guaranteed to be nul-terminated. Before recent commit 7eab73b18630 ("netconsole: convert to NBCON console infrastructure") the message would be placed in printk_shared_pbufs, a static global buffer, so KASAN had harder time catching OOB accesses. Now we see: printk: console [netcon_ext0] enabled BUG: KASAN: slab-out-of-bounds in string+0x1f7/0x240 Read of size 1 at addr ffff88813b6d4c00 by task pr/netcon_ext0/594 CPU: 65 UID: 0 PID: 594 Comm: pr/netcon_ext0 Not tainted 6.19.0-11754-g4246fd6547c9 Call Trace: kasan_report+0xe4/0x120 string+0x1f7/0x240 vsnprintf+0x655/0xba0 scnprintf+0xba/0x120 netconsole_write+0x3fe/0xa10 nbcon_emit_next_record+0x46e/0x860 nbcon_kthread_func+0x623/0x750 Allocated by task 1: nbcon_alloc+0x1ea/0x450 register_console+0x26b/0xe10 init_netconsole+0xbb0/0xda0 The buggy address belongs to the object at ffff88813b6d4000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes to the right of allocated 3072-byte region [ffff88813b6d4000, ffff88813b6d4c00)

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected products

Linux Kernel≥ 6.19 < 6.19.6 · ≥ 6.6 < 6.18.16 · 7.0

Remediation

Fixed in

Linux Kernel≥ 6.19.6

Patch & vendor advisories

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-43197 being actively exploited?

CVE-2026-43197 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.65%.

How severe is CVE-2026-43197?

CVE-2026-43197 has a CVSS 3.1 base score of 9.1, rated critical. EPSS estimates a 0.65% probability of exploitation.

Which products are affected by CVE-2026-43197?

Affected products include Linux Kernel.

How do I fix CVE-2026-43197?

Upgrade affected software to a fixed version, for example Linux Kernel 6.19.6 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

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