CVE-2026-43190
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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).
- CVSS 3.1
- 8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
- EPSS
- 0.46% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/07a9b32eaae792ff7d0fcac14d8920c937c0a9c3Patch
- https://git.kernel.org/stable/c/5e13d0a37666955b6cfddc0f73cb40ed645b8a05Patch
- https://git.kernel.org/stable/c/735ee8582da3d239eb0c7a53adca61b79fb228b3Patch
- https://git.kernel.org/stable/c/8b300f726640c48c3edfe9c453334dd801f4b74ePatch
- https://git.kernel.org/stable/c/cd5beda7e0e32865e214f28034bb92c1cecff885Patch
- https://git.kernel.org/stable/c/eaedc0bc18be46fe7f58170e967959a932c4f824Patch
- https://git.kernel.org/stable/c/f6c412dcfd76b0516d51aa847d8f4c7b70381b09Patch
- https://git.kernel.org/stable/c/f895191dc32c53eaf443b6443fe40945b2f92287Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.