CVE-2026-31698

High

In the Linux kernel, the following vulnerability has been resolved: crypto: ccp: Don't attempt to copy PDH cert to userspace if PSP command failed When retrieving the PDH cert, don't attempt to copy the blobs to userspace if the firmware command failed. If the failure was due to an invalid length, i.e. the userspace buffer+length was too small, copying the number of bytes _firmware_ requires will overflow the kernel-allocated buffer and leak data to userspace. BUG: KASAN: slab-out-of-bounds in instrument_copy_to_user ../include/linux/instrumented.h:129 [inline] BUG: KASAN: slab-out-of-bounds in _inline_copy_to_user ../include/linux/uaccess.h:205 [inline] BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26 Read of size 2084 at addr ffff8885c4ab8aa0 by task syz.0.186/21033 CPU: 51 UID: 0 PID: 21033 Comm: syz.0.186 Tainted: G U O 7.0.0-smp-DEV #28 PREEMPTLAZY Tainted: [U]=USER, [O]=OOT_MODULE Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.84.12-0 11/17/2025 Call Trace: <TASK> dump_stack_lvl+0xc5/0x110 ../lib/dump_stack.c:120 print_address_description ../mm/kasan/report.c:378 [inline] print_report+0xbc/0x260 ../mm/kasan/report.c:482 kasan_report+0xa2/0xe0 ../mm/kasan/report.c:595 check_region_inline ../mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 ../mm/kasan/generic.c:200 instrument_copy_to_user ../include/linux/instrumented.h:129 [inline] _inline_copy_to_user ../include/linux/uaccess.h:205 [inline] _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26 copy_to_user ../include/linux/uaccess.h:236 [inline] sev_ioctl_do_pdh_export+0x3d3/0x7c0 ../drivers/crypto/ccp/sev-dev.c:2347 sev_ioctl+0x2a2/0x490 ../drivers/crypto/ccp/sev-dev.c:2568 vfs_ioctl ../fs/ioctl.c:51 [inline] __do_sys_ioctl ../fs/ioctl.c:597 [inline] __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:583 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe0/0x800 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> WARN if the driver says the command succeeded, but the firmware error code says otherwise, as __sev_do_cmd_locked() is expected to return -EIO on any firwmware error.

Package Linux Kernel
Published 2026-05-01
Last modified 2026-06-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.1

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness type

CWE-787

CVE-2026-31698 is a Out-of-bounds Write vulnerability

What is Out-of-bounds Write?

The product writes data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.16 and later are affected. Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.84, 6.18.25, 7.0.2, 7.1-rc1 and their respective stable series.

Affected from
≥ 4.16
Fixed in
✓ 5.10.258 5.10.x ✓ 5.15.209 5.15.x ✓ 6.1.175 6.1.x ✓ 6.6.136 6.6.x ✓ 6.12.84 6.12.x ✓ 6.18.25 6.18.x ✓ 7.0.2 7.0.x ✓ 7.1-rc1

References

The following references provide additional information about CVE-2026-31698 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

8 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-31698?

    CVE-2026-31698 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 , classified as an Out-of-bounds Write flaw (CWE-787) . It affects Linux kernel versions from 4.16 onward and has been patched in 5.10.258, 5.15.209, 6.1.175 and others. CVE-2026-31698 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31698?

    CVE-2026-31698 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H .

  • Is there a patch available for CVE-2026-31698?

    Yes — CVE-2026-31698 has been patched. Fixed versions include 5.10.258, 5.15.209, 6.1.175 and others. If you are running Linux kernel 4.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-31698 actively exploited?

    No — CVE-2026-31698 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Out-of-bounds Write (CWE-787)?

    The product writes data past the end or before the beginning of the intended buffer. View CWE-787 on MITRE CWE →

Back to
All CVEs
View on
NVD / NIST