In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_tcpmss: check remaining length before reading optlen Quoting… (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 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).
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_tcpmss: check remaining length before reading optlen Quoting… (CVE-2026-43190)
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 v3.1
Score 8.2high
Affected software
pkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/[email protected]~14.04.1?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/[email protected]~14.04.1?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]~16.04.1?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=fips/xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]~18.04.2?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email 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protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]~18.04.1?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips-updates/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=fips/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email protected]~20.04.1?arch=source&distro=focalpkg:deb/ubuntu/[email 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protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-43190
- Osv Schema Version
- 1.7.0
- Aliases
- []
- Ecosystems
- ["Ubuntu:Pro:14.04:LTS","Ubuntu:Pro:16.04:LTS","Ubuntu:16.04:LTS","Ubuntu:Pro:FIPS:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:18.04:LTS","Ubuntu:Pro:FIPS-updates:18.04:LTS","Ubuntu:Pro:FIPS:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:20.04:LTS","Ubuntu:Pro:FIPS-updates:20.04:LTS","Ubuntu:Pro:FIPS:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:Nvidia-BlueField:22.04:LTS","Ubuntu:Pro:FIPS-preview:22.04:LTS","Ubuntu:Pro:FIPS-updates:22.04:LTS","Ubuntu:Pro:Realtime:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:Nvidia-BlueField:24.04:LTS","Ubuntu:Pro:FIPS-updates:24.04:LTS","Ubuntu:Pro:Realtime:24.04:LTS","Ubuntu:25.10","Ubuntu:26.04:LTS"]
- Database Specific Severity
- null
- Cvss Version
- 4.0
Threat ID: 6a5b61762d1edb114c862d6d
Added to database: 07/18/2026, 11:20:22 UTC
Last updated: 07/31/2026, 21:29:08 UTC
Views: 2
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