Answer in brief
CVE-2026-43190 records a Unknown severity vulnerability in netfilter: xt_tcpmss: check remaining length before reading optlen. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-43190 records a Unknown severity vulnerability in netfilter: xt_tcpmss: check remaining length before reading optlen. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f895191dc32c53eaf443b6443fe40945b2f92287 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cd5beda7e0e32865e214f28034bb92c1cecff885 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <eaedc0bc18be46fe7f58170e967959a932c4f824 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <07a9b32eaae792ff7d0fcac14d8920c937c0a9c3 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b300f726640c48c3edfe9c453334dd801f4b74e || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5e13d0a37666955b6cfddc0f73cb40ed645b8a05 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f6c412dcfd76b0516d51aa847d8f4c7b70381b09 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <735ee8582da3d239eb0c7a53adca61b79fb228b3 | f895191dc32c53eaf443b6443fe40945b2f92287, cd5beda7e0e32865e214f28034bb92c1cecff885, eaedc0bc18be46fe7f58170e967959a932c4f824, 07a9b32eaae792ff7d0fcac14d8920c937c0a9c3, 8b300f726640c48c3edfe9c453334dd801f4b74e, 5e13d0a37666955b6cfddc0f73cb40ed645b8a05, f6c412dcfd76b0516d51aa847d8f4c7b70381b09, 735ee8582da3d239eb0c7a53adca61b79fb228b3 |
| Linux/Linuxgeneric | 2.6.12 | Not reported |
Published upstream
May 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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).
Quoted source text, attributed separately from HOL analysis.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f895191dc32c53eaf443b6443fe40945b2f92287 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cd5beda7e0e32865e214f28034bb92c1cecff885 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <eaedc0bc18be46fe7f58170e967959a932c4f824 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <07a9b32eaae792ff7d0fcac14d8920c937c0a9c3 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b300f726640c48c3edfe9c453334dd801f4b74e || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5e13d0a37666955b6cfddc0f73cb40ed645b8a05 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f6c412dcfd76b0516d51aa847d8f4c7b70381b09 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <735ee8582da3d239eb0c7a53adca61b79fb228b3 | f895191dc32c53eaf443b6443fe40945b2f92287, cd5beda7e0e32865e214f28034bb92c1cecff885, eaedc0bc18be46fe7f58170e967959a932c4f824, 07a9b32eaae792ff7d0fcac14d8920c937c0a9c3, 8b300f726640c48c3edfe9c453334dd801f4b74e, 5e13d0a37666955b6cfddc0f73cb40ed645b8a05, f6c412dcfd76b0516d51aa847d8f4c7b70381b09, 735ee8582da3d239eb0c7a53adca61b79fb228b3 |
| Linux/Linuxgeneric | 2.6.12 | Not reported |
Published upstream
May 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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).
Quoted source text, attributed separately from HOL analysis.