CVE-2026-53173 [High] | Out-of-bounds Write in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: accel/ethosu: fix OOB write in ethosu_gem_cmdstream_copy_and_validate() The command stream parsing loop increments the index variable a second time when a 64-bit command word is encountered (bit 14 set), but does not re-check the loop bound before writing the second word: for (i = 0; i < size / 4; i++) { bocmds[i] = cmds[0]; if (cmd & 0x4000) { i++; bocmds[i] = cmds[1]; /* unchecked */ } } The buffer bocmds is backed by a DMA allocation of exactly size bytes from drm_gem_dma_create(ddev, size), giving valid indices [0, size/4-1]. When i == size/4 - 1 on entry to an iteration and bit 14 of cmds[0] is set, bocmds[size/4-1] is written in bounds, i is then incremented to size/4, and bocmds[size/4] writes four bytes past the end of the allocation. Userspace controls both the buffer contents and the size argument via the ioctl, making this a userspace-triggerable heap out-of-bounds write. Fix by checking the incremented index against the buffer bound before the second write and returning -EINVAL if the buffer is too small to contain the extended command.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-28	0.16%	0.13%	-0.03%
2	2026-06-25	—	0.16%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-28

0.16%

0.13%

-0.03%

2026-06-25

—

0.16%

—

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	416baaa9-dc9f-4396-8d5f-8c081fb06d67

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

416baaa9-dc9f-4396-8d5f-8c081fb06d67

OS Trackers for CVE-2026-53173

vendor	priority	summary	link
`debian`	unimportant	CVE-2026-53173 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-2026-53173
`redhat`	—	—	https://access.redhat.com/security/cve/CVE-2026-53173
`suse`	medium	CVE-2026-53173 severity moderate: SUSE including 21 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 199 product×package rows across 40 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (40 product lines)): Known Not Affected 199.	https://www.suse.com/security/cve/CVE-2026-53173/
`ubuntu`	high	CVE-2026-53173 high priority: Ubuntu including 162 source packages (linux, linux-allwinner-5.19, …), 1458 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1051, ignored 172, not-affected 131, released 88, needed 16.	https://ubuntu.com/security/CVE-2026-53173

Affected software / configurations for CVE-2026-53173

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 6.19, < 7.0.13	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	7.1	cpe:2.3:o:linux:linux_kernel:7.1:rc1::::::
linux	linux_kernel	7.1	cpe:2.3:o:linux:linux_kernel:7.1:rc2::::::
linux	linux_kernel	7.1	cpe:2.3:o:linux:linux_kernel:7.1:rc3::::::
linux	linux_kernel	7.1	cpe:2.3:o:linux:linux_kernel:7.1:rc4::::::
linux	linux_kernel	7.1	cpe:2.3:o:linux:linux_kernel:7.1:rc5::::::
linux	linux_kernel	7.1	cpe:2.3:o:linux:linux_kernel:7.1:rc6::::::

References for CVE-2026-53173

URL	Tags
https://git.kernel.org/stable/c/c0837b9cf6eabbad8b8cbddaff1a46a6d0a2e29d	Patch
https://git.kernel.org/stable/c/db6cb3e35cebf487f9a78ebd4cfa4b83708ff40d	Patch

URL

CVE-2026-53173 | accel/ethosu: fix OOB write in ethosu_gem_cmdstream_copy_and_validate()

Exploit prediction scoring system (EPSS) score for CVE-2026-53173

Common vulnerability scoring system (CVSS) metrics for CVE-2026-53173

Weakness enumeration for CVE-2026-53173

GitHub Security Advisory for CVE-2026-53173

OS Trackers for CVE-2026-53173

Affected software / configurations for CVE-2026-53173

References for CVE-2026-53173