CVE-2025-38688 [High] | Security Vulnerability in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: iommufd: Prevent ALIGN() overflow When allocating IOVA the candidate range gets aligned to the target alignment. If the range is close to ULONG_MAX then the ALIGN() can wrap resulting in a corrupted iova. Open code the ALIGN() using get_add_overflow() to prevent this. This simplifies the checks as we don't need to check for length earlier either. Consolidate the two copies of this code under a single helper. This bug would allow userspace to create a mapping that overlaps with some other mapping or a reserved range.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.02%	0.15%	+0.13%
2	2025-09-05	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.02%

0.15%

+0.13%

2025-09-05

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

[email protected]

OS Trackers for CVE-2025-38688

vendor	priority	summary	link
`debian`	unimportant	CVE-2025-38688 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2025-38688
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2025-38688
`suse`	medium	CVE-2025-38688 severity moderate: SUSE including 18 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 141 product×package rows across 29 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS, … (29 product lines)): Known Not Affected 141.	https://www.suse.com/security/cve/CVE-2025-38688/
`ubuntu`	medium	CVE-2025-38688 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 176, released 118, not-affected 95, needed 5, needs-triage 2, pending 1.	https://ubuntu.com/security/CVE-2025-38688

Affected software / configurations for CVE-2025-38688

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 6.2, < 6.6.103	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.7, < 6.12.43	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.15.11	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.16, < 6.16.2	cpe:2.3:o:linux:linux_kernel::::::::

References for CVE-2025-38688

URL	Tags
https://git.kernel.org/stable/c/79fad1917802c28de51a479318a056a6fbe3e2f2	Patch
https://git.kernel.org/stable/c/b42497e3c0e74db061eafad41c0cd7243c46436b	Patch
https://git.kernel.org/stable/c/d19b817540c0abe84854a64ee9ee34cecc3bbeef	Patch
https://git.kernel.org/stable/c/e42a046bb41dcdde4f766a17d8211842007ed537	Patch
https://git.kernel.org/stable/c/ebb6021560b94649bec6b8faba6fe0dca2218e81	Patch

URL

CVE-2025-38688 | iommufd: Prevent ALIGN() overflow

Exploit prediction scoring system (EPSS) score for CVE-2025-38688

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38688

Weakness enumeration for CVE-2025-38688

OS Trackers for CVE-2025-38688

Affected software / configurations for CVE-2025-38688

References for CVE-2025-38688