CVE-2026-43190
What it is
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_tcpmss: check remaining length before reading optlen Quoting reporter: In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads op[i+1] directly without validating the remaining option length. If the last byte of the option field is not EOL/NOP (0/1), the code attempts to index op[i+1]. In the case where i + 1 == optlen, this causes an out-of-bounds read, accessing memory past the optlen boundary (either reading beyond the stack buffer _opt or the following payload).
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of service disruption.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 8.2 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Modified
Affected
- Linux Kernel < 5.10.252
- Linux Kernel < 5.15.202
- Linux Kernel < 6.1.165
- Linux Kernel < 6.6.128
- Linux Kernel < 6.12.75
- Linux Kernel < 6.18.16
- Linux Kernel < 6.19.6
- Linux Kernel 2.6.12
Attack profile CVSS 3.1 · 8.2
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-43190.md and follow it. Check whether this project is affected by CVE-2026-43190. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/07a9b32eaae792ff7d0fcac14d8920c937c0a9c3
- https://git.kernel.org/stable/c/5e13d0a37666955b6cfddc0f73cb40ed645b8a05
- https://git.kernel.org/stable/c/735ee8582da3d239eb0c7a53adca61b79fb228b3
- https://git.kernel.org/stable/c/8b300f726640c48c3edfe9c453334dd801f4b74e
- https://git.kernel.org/stable/c/cd5beda7e0e32865e214f28034bb92c1cecff885
- https://git.kernel.org/stable/c/eaedc0bc18be46fe7f58170e967959a932c4f824
- https://git.kernel.org/stable/c/f6c412dcfd76b0516d51aa847d8f4c7b70381b09
- https://git.kernel.org/stable/c/f895191dc32c53eaf443b6443fe40945b2f92287
References
- https://git.kernel.org/stable/c/07a9b32eaae792ff7d0fcac14d8920c937c0a9c3
- https://git.kernel.org/stable/c/5e13d0a37666955b6cfddc0f73cb40ed645b8a05
- https://git.kernel.org/stable/c/735ee8582da3d239eb0c7a53adca61b79fb228b3
- https://git.kernel.org/stable/c/8b300f726640c48c3edfe9c453334dd801f4b74e
- https://git.kernel.org/stable/c/cd5beda7e0e32865e214f28034bb92c1cecff885
- https://git.kernel.org/stable/c/eaedc0bc18be46fe7f58170e967959a932c4f824
- https://git.kernel.org/stable/c/f6c412dcfd76b0516d51aa847d8f4c7b70381b09
- https://git.kernel.org/stable/c/f895191dc32c53eaf443b6443fe40945b2f92287