PT-2026-36444 · Linux · Linux Kernel

Published 2026-05-01 · Updated 2026-05-01 · CVE-2026-43027

Positive Technologies (AI Summary)

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A use-after-free issue exists in the netfilter nf conntrack helper component. The function nf conntrack helper unregister() calls nf ct expect iterate destroy() to remove expectations associated with a helper being unregistered, but it incorrectly passes NULL instead of the helper pointer as the data argument. Consequently, expect iter me() fails to match any expectations, leaving them active. When nfnl cthelper del() subsequently frees the helper object, later expectation dumps or packet-driven init conntrack() calls dereference the freed exp->helper pointer.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2026-43027

Affected Products

Linux Kernel

References · 10

• https://nvd.nist.gov/vuln/detail/CVE-2026-43027 · Security Note
• https://git.kernel.org/stable/c/2c16e4d64dd91227742dfe196a3e7b0568bef65a · Note
• https://git.kernel.org/stable/c/2cf2737c85a2ba2b52024dafe68ffad2676f97be · Note
• https://git.kernel.org/stable/c/a242a9ae58aa46ff7dae51ce64150a93957abe65 · Note
• https://git.kernel.org/stable/c/dc1739eff48e34cc71d4e2f03715493fbcebd8af · Note
• https://git.kernel.org/stable/c/620f3d14c1ef51d425060a3056ad8dbae8f998a3 · Note
• https://git.kernel.org/stable/c/90bd7e8501349db3006d21fbc09df9ffcb172965 · Note
• https://git.kernel.org/stable/c/5cf28d5c8dcbbe8af6d3b145babe491906d7bad1 · Note
• https://git.kernel.org/stable/c/504ba4168466c91210c45acdc332479cfd5f2da6 · Note
• https://twitter.com/vuldb/status/2050245433067446533 · Twitter Post