CVE-2025-21950 [High] | Information Disclosure in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: drivers: virt: acrn: hsm: Use kzalloc to avoid info leak in pmcmd_ioctl In the "pmcmd_ioctl" function, three memory objects allocated by kmalloc are initialized by "hcall_get_cpu_state", which are then copied to user space. The initializer is indeed implemented in "acrn_hypercall2" (arch/x86/include/asm/acrn.h). There is a risk of information leakage due to uninitialized bytes.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-05-11	0.06%	0.01%	-0.05%
2	2026-01-26	0.02%	0.06%	+0.04%
3	2026-01-23	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-05-11

0.06%

0.01%

-0.05%

2026-01-26

0.02%

0.06%

+0.04%

2026-01-23

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.1	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.2	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.1

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.2

[email protected]

OS Trackers for CVE-2025-21950

vendor	priority	summary	link
`debian`	unimportant	CVE-2025-21950 unimportant priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6.	https://security-tracker.debian.org/tracker/CVE-2025-21950
`redhat`	—	—	https://access.redhat.com/security/cve/CVE-2025-21950
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2025-21950/
`ubuntu`	medium	CVE-2025-21950 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, released 170, ignored 150, not-affected 85, needed 1.	https://ubuntu.com/security/CVE-2025-21950

Affected software / configurations for CVE-2025-21950

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 5.12, < 5.15.179	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.1.131	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.2, < 6.6.83	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.7, < 6.12.19	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.13.7	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	6.14	cpe:2.3:o:linux:linux_kernel:6.14:rc1::::::
linux	linux_kernel	6.14	cpe:2.3:o:linux:linux_kernel:6.14:rc2::::::
linux	linux_kernel	6.14	cpe:2.3:o:linux:linux_kernel:6.14:rc3::::::
linux	linux_kernel	6.14	cpe:2.3:o:linux:linux_kernel:6.14:rc4::::::
linux	linux_kernel	6.14	cpe:2.3:o:linux:linux_kernel:6.14:rc5::::::
debian	debian_linux	11.0	cpe:2.3:o:debian:debian_linux:11.0:::::::*

References for CVE-2025-21950

URL	Tags
https://git.kernel.org/stable/c/1b8f7a2caa7f9cdfd135e3f78eb9d7e36fb95083	Patch
https://git.kernel.org/stable/c/4e15cf870d2c748e45d45ffc4d5b1dc1b7d50120	Patch
https://git.kernel.org/stable/c/524f29d78c9bdeb49f31f5b0376a07d2fc5cf563	Patch
https://git.kernel.org/stable/c/819cec1dc47cdeac8f5dd6ba81c1dbee2a68c3bb	Patch
https://git.kernel.org/stable/c/a4c21b878f0e237f45209a324c903ea7fb05247d	Patch
https://git.kernel.org/stable/c/d7e5031fe3f161c8eb5e84db1540bc4373ed861b	Patch
https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html	Third Party Advisory

URL

CVE-2025-21950 | drivers: virt: acrn: hsm: Use kzalloc to avoid info leak in pmcmd_ioctl

Exploit prediction scoring system (EPSS) score for CVE-2025-21950

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21950

Weakness enumeration for CVE-2025-21950

OS Trackers for CVE-2025-21950

Affected software / configurations for CVE-2025-21950

References for CVE-2025-21950