CVE-2026-43190
netfilter: xt_tcpmss: check remaining length before reading optlen
Using Linux by Linux?
Get instant alerts when new vulnerabilities affect Linux - before attackers find them.
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).
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- https://git.kernel.org/stable/c/f895191dc32c53eaf443b6443fe40945b2f92287
- https://git.kernel.org/stable/c/cd5beda7e0e32865e214f28034bb92c1cecff885
- https://git.kernel.org/stable/c/eaedc0bc18be46fe7f58170e967959a932c4f824
- https://git.kernel.org/stable/c/07a9b32eaae792ff7d0fcac14d8920c937c0a9c3
- https://git.kernel.org/stable/c/8b300f726640c48c3edfe9c453334dd801f4b74e
References (8)
SSVC — Action Prioritization
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
Quick Info
Get alerted
Stop reading CVE feeds looking for your own stack
Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.