7.1

CVE-2026-31698: crypto: ccp: Don't attempt to copy PDH cert to userspace if PSP command failed

Modified
AliasesUBUNTU-CVE-2026-31698DEBIAN-CVE-2026-31698CGA-56rc-w3xh-9f4x
Published 01-05-2026Last modified 19-10-2026

Vulnerability summary

CVE-2026-31698 is a high (CVSS 7.1) Out-of-bounds Write vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.1, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.13%
0%100%
Low · -0.04 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 52 · Related 51
MGASA-2026-0108MGASA-2026-0110OPENSUSE-SU-2026:10793-1OPENSUSE-SU-2026:21555-1SUSE-SU-2026:22433-1SUSE-SU-2026:22436-1

Timeline

  1. 01-05-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.13%

Chance of exploitation in the next 30 days

Percentile

3%

Versus all other CVEs

30-day change

Decrease -0.04 pp

From 0.17% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu154 products
  • linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136 | < 7.0.0-27.27
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64 | < 7.0.0-1008.8
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Chainguard6 products
  • linux-aws-6.18< 6.18.31-r0
  • linux-azure-6.18< 6.18.31-r0 | < 6.18.24-r1
  • linux-gcp-6.18< 6.18.31-r0
  • linux-qemu-6.18< 6.18.24-r3
  • linux-qemu-rc< 7.1_rc3-r0
Linux2 products
  • linux≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < af67d35da744b6b678c7a0296d9c679658779829 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 854d7846e1d29f32f1bbeb2e869e794df12067f6 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 25d9b3446001185484209cf57951f3368462b631 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < b5c14bd4da1f376f385722fe1da993f1edab6472 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 78b97e43d0b3e674d9d49ae56937b11e2ba3fcaf | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 051e51aa55fd4cdc3e8283cf4476aeeb5f563274 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 50808c13452dae43a2c90b1bbbf9daa16501ce70 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < e76239fed3cffd6d304d8ca3ce23984fd24f57d3 | 4.16
  • linux_kernel≥ 4.16, < 6.6.136 | ≥ 6.7, < 6.12.84 | ≥ 6.13, < 6.18.25 | ≥ 6.19, < 7.0.2 | 7.1:rc1 | 7.1:rc2
Debian1 product
  • linux< 6.1.176-1 | < 6.12.85-1 | < 7.0.3-1

4 vendors · 163 products

References

48 links
Show all 48 references