Out-of-bounds Read Affecting kernel-rt-debug package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RHEL10-KERNELRTDEBUG-19482722
- published2 Sept 2026
- disclosed15 Aug 2026
Introduced: 15 Aug 2026
NewCVE-2026-74485 (opens in a new tab)How to fix?
There is no fixed version for RHEL:10 kernel-rt-debug.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug package and not the kernel-rt-debug package as distributed by RHEL.
See How to fix? for RHEL:10 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
binfmt_misc: reject a flag character as the field delimiter
The registration string starts with a user chosen delimiter that separates the individual fields. So that the field parsers terminate even on a truncated string create_entry() pads the buffer with that same delimiter:
memset(buf + count, del, 8);
Most fields are scanned for the delimiter with strchr()/scanarg() and happily stop on the padding. The flags field is different: instead of scanning for the delimiter check_special_flags() consumes the flag characters 'P', 'O', 'C' and 'F' and stops at the first byte that is none of them, relying on the trailing delimiter to end the scan.
If the delimiter is itself a flag character the padding no longer acts as a terminator. The scan swallows all eight padding bytes and keeps reading past the end of the allocation until it hits a byte that is not a flag character. For example registering
PaPEPPxPPiP
with 'P' as the delimiter (name "a", type extension, magic "x", interpreter "i", empty flags) leaves the flag scan running off the end of the buffer. The registration is rejected in the end because the parser does not stop exactly at buf + count, but only after the out of bounds read has already happened. With an unlucky allocation layout the scan can walk into an unmapped page; under KASAN it is reported as a slab out of bounds read. binfmt_misc mounts are available to unprivileged users in a user namespace so the read is reachable without privileges.
Reject a delimiter that is one of the flag characters up front. Such a registration was always rejected anyway, only after the out of bounds read, so no valid registration string changes meaning.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2517031
- https://access.redhat.com/security/cve/CVE-2026-74485
- https://git.kernel.org/stable/c/1819f82dee766c58295ecaacdac02cdf6837d7a4
- https://git.kernel.org/stable/c/1853e95c9bfe69ef1dd862b3f551e68f4a1b76cc
- https://git.kernel.org/stable/c/840bb9c49c3e75fb32b593d67ab32f6b77122262
- https://git.kernel.org/stable/c/8e85d50ba1117fd446bf9a250bd8a97d48384bdc
- https://git.kernel.org/stable/c/9a2d87db3898b5993b64fd258d0334e0eba9ee0d
- https://git.kernel.org/stable/c/96bd5d4fea2970b9b08265293ca7a10b9b27c0fd
- https://git.kernel.org/stable/c/9970e094e5d60f0d66914bf9a97d1ef19107ebf5
- https://git.kernel.org/stable/c/b29e3c1f375c1296362d219ff38bceddf2d2a88a