Description
In the Linux kernel, the following vulnerability has been resolved: capabilities: fix undefined behavior in bit shift for CAP_TO_MASK Shifting signed 32-bit value by 31 bits is undefined, so changing significant bit to unsigned. The UBSAN warning calltrace like below: UBSAN: shift-out-of-bounds in security/commoncap.c:1252:2 left shift of 1 by 31 places cannot be represented in type 'int' Call Trace: <TASK> dump_stack_lvl+0x7d/0xa5 dump_stack+0x15/0x1b ubsan_epilogue+0xe/0x4e __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c cap_task_prctl+0x561/0x6f0 security_task_prctl+0x5a/0xb0 __x64_sys_prctl+0x61/0x8f0 do_syscall_64+0x58/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK>
Affected products
linux: linux kernel
References8
- git.kernel.org/stable/c/151dc8087b5609e53b069c068e3f3ee100efa586 Patch
- git.kernel.org/stable/c/27bdb134c043ff32c459d98f16550d0ffa0b3c34 Patch
- git.kernel.org/stable/c/46653972e3ea64f79e7f8ae3aa41a4d3fdb70a13 Patch
- git.kernel.org/stable/c/5661f111a1616ac105ec8cec81bff99b60f847ac Patch
- git.kernel.org/stable/c/5b79fa628e2ab789e629a83cd211ef9b4c1a593e Patch
- git.kernel.org/stable/c/65b0bc7a0690861812ade523d19f82688ab819dc Patch
- git.kernel.org/stable/c/dbaab08c8677d598244d21afb7818e44e1c5d826 Patch
- git.kernel.org/stable/c/fcbd2b336834bd24e1d9454ad5737856470c10d7 Patch
Metrics
- CVSS 3.1
-
7.1
HIGH
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H - EPSS — exploit probability
- 0% percentile: 13 · as of 7 November 2026
- CWE
- CWE-125
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.