CVE-2026-43190
Published: May 7, 2026Last modified: May 7, 2026
Description
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).
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 8.2 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | LOW |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.167-r0) |
| 25 LTS | linux-lts | Fixed (6.12.80-r0) | |
| Stream | linux-lts | Fixed (6.12.76-r0) |
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