CVE-2026-46333

Summary

In the Linux kernel, the following vulnerability has been resolved:

ptrace: slightly saner 'get_dumpable()' logic

The 'dumpability' of a task is fundamentally about the memory image of the task - the concept comes from whether it can core dump or not - and makes no sense when you don't have an associated mm.

And almost all users do in fact use it only for the case where the task has a mm pointer.

But we have one odd special case: ptrace_may_access() uses 'dumpable' to check various other things entirely independently of the MM (typically explicitly using flags like PTRACE_MODE_READ_FSCREDS). Including for threads that no longer have a VM (and maybe never did, like most kernel threads).

It's not what this flag was designed for, but it is what it is.

The ptrace code does check that the uid/gid matches, so you do have to be uid-0 to see kernel thread details, but this means that the traditional "drop capabilities" model doesn't make any difference for this all.

Make it all make a bit more sense by saying that if you don't have a MM pointer, we'll use a cached "last dumpability" flag if the thread ever had a MM (it will be zero for kernel threads since it is never set), and require a proper CAP_SYS_PTRACE capability to override.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxbfedb589252c01fa505ac9f6f2a3d5d68d707ef4 < 93d4ba49d18e3d7fb41a9927c2d0cca5e9dfefd6affected
LinuxLinuxbfedb589252c01fa505ac9f6f2a3d5d68d707ef4 < 15b828a46f305ae9f05a7c16914b3ce273474205affected
LinuxLinuxbfedb589252c01fa505ac9f6f2a3d5d68d707ef4 < 4709234fd1b95136ceb789f639b1e7ea5de1b181affected
LinuxLinuxbfedb589252c01fa505ac9f6f2a3d5d68d707ef4 < 8f907d345bae8f4b3f004c5abc56bf2dfb851ea7affected
LinuxLinuxbfedb589252c01fa505ac9f6f2a3d5d68d707ef4 < 6e5b51e74a40d377bcd3081dd33fbaa0e1aa7e3daffected
LinuxLinuxbfedb589252c01fa505ac9f6f2a3d5d68d707ef4 < 2a93a4fac7b6051d3be7cd1b015fe7320cd0404daffected
LinuxLinuxbfedb589252c01fa505ac9f6f2a3d5d68d707ef4 < 01363cb3fbd0238ffdeb09f53e9039c9edf8a730affected
LinuxLinuxbfedb589252c01fa505ac9f6f2a3d5d68d707ef4 < 31e62c2ebbfdc3fe3dbdf5e02c92a9dc67087a3aaffected
LinuxLinuxd5b3e840dbf6dd2c0f30b5982b6f5ecd49e46b12affected
LinuxLinux03eed7afbc09e061f66b448daf7863174c3dc3f3affected
LinuxLinuxe45692fa1aea06676449b63ef3c2b6e1e72b7578affected
LinuxLinux694a95fa6dae4991f16cda333d897ea063021fedaffected
LinuxLinux3.16.52 < 3.17affected
LinuxLinux4.4.40 < 4.5affected
LinuxLinux4.8.16 < 4.9affected
LinuxLinux4.9.1 < 4.10affected
LinuxLinux4.10affected
LinuxLinux0 < 4.10unaffected
LinuxLinux5.10.256 <= 5.10.*unaffected
LinuxLinux5.15.207 <= 5.15.*unaffected
LinuxLinux6.1.173 <= 6.1.*unaffected
LinuxLinux6.6.139 <= 6.6.*unaffected
LinuxLinux6.12.89 <= 6.12.*unaffected
LinuxLinux6.18.31 <= 6.18.*unaffected
LinuxLinux7.0.8 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: total

Additional References

kernel: Read root-owned files as an unprivileged user

Additional References

References