Live › vulnerability › CVE-2026-98856
Go to dashboardIn the Linux kernel's kprobes code on x86, arming a new probe can overwrite part of an existing optimized probe's jump, so execution can jump to the wrong address. The sources do not state a confirmed attacker outcome beyond wrong-address execution.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Systems running a Linux kernel on x86 that use kprobes with optimized probes. Systems without kprobe use or on non-x86 architectures are likely not affected, but the sources do not confirm this.
No product ranges from the sources yet.
uname -r and compare against a kernel build that includes the upstream fix for CVE-2026-98856Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
kprobes: Skip disarmed probes when checking optkprobe overlap
On x86, an optkprobe at A replaces five bytes with a jump. If a disabled probe B is at A+2, get_optimized_kprobe() stops at B when arming a new probe C at A+4. It leaves A optimized:
A A+1 A+2 A+3 A+4
A's jump | e9 | d0 | d1 | d2 | d3 | after C | e9 | d0 | d1 | d2 | cc |
The INT3 for C overwrites the last byte of A's jump displacement, so execution can jump to the wrong address. B can have prepared optinsns while disarmed, but has no jump to unoptimize.
Continue past disarmed and unprepared probes to find the active optimized probe before arming a probe in its jump.
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