Rapid7

module

rxkad Page-Cache Write via CVE-2026-43500

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Disclosed
May 8, 2026
Created
May 21, 2026

Description

CVE-2026-43500 exploits a memory-corruption vulnerability in the Linux kernel's RxRPC
authentication subsystem (rxkad). When a crafted DATA packet is delivered to an AF_RXRPC
socket configured with an attacker-controlled rxkad session key, the kernel's
rxkad_verify_packet_1() function performs an in-place 8-byte pcbc(fcrypt) decryption
directly on the page-cache page referenced by the splice offset. Because the decryption
mutates the page in-place without marking it dirty, the corrupted in-memory view is
immediately visible to all processes reading from the page cache. This allows a local
attacker to corrupt the in-memory contents of a SUID binary and escalate privileges to root.

Authors

Hyunwoo Kim
Giovanni Heward

Platform

Linux,Unix

Architectures

cmd

References

Module Options

To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':


    msf > use exploit/linux/local/cve_2026_43500_dirty_frag
    msf exploit(cve_2026_43500_dirty_frag) > show targets
        ...targets...
    msf exploit(cve_2026_43500_dirty_frag) > set TARGET < target-id >
    msf exploit(cve_2026_43500_dirty_frag) > show options
        ...show and set options...
    msf exploit(cve_2026_43500_dirty_frag) > exploit
Title
Rapid7 Labs

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