CVE-2026-68186

Technical Description

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

binfmt_misc: set have_execfd only once the interpreter is opened

load_misc_binary() raises bprm->have_execfd as soon as it sees the 'O'

(or 'C') flag. This happens well before it opens the interpreter. If

that open fails the flag stays set on the bprm. binfmt_misc is at the

head of the format list so an interpreter open failure that returns

-ENOEXEC lets the search fall through to a later format. This means it

runs the matched binary directly having never staged an interpreter. So

bprm->executable is NULL while have_execfd falsely claims a descriptor

is present.

Consequently, begin_new_exec() dereferences the missing executable:

would_dump(bprm, bprm->executable);

and NULL derefs. Had it not, the hand-off later in the same function

would have failed anyway. FD_ADD(0, bprm->executable) rejects a NULL

file with -ENOMEM. Both sites are past the point of no return so the

exec cannot be unwound either way.

This can

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References