7.1

CVE-2026-31614: smb: client: fix off-by-8 bounds check in check_wsl_eas()

Analyzed
AliasesUBUNTU-CVE-2026-31614DEBIAN-CVE-2026-31614CGA-9j6f-3vrr-pfpf
Published 24-04-2026Last modified 14-06-2026

Vulnerability summary

CVE-2026-31614 is a high (CVSS 7.1) Out-of-bounds Read vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.2% 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 (NVD)
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 17 · Related 18
OPENSUSE-SU-2026:10703-1SUSE-SU-2026:22043-1SUSE-SU-2026:22048-1SUSE-SU-2026:22076-1SUSE-SU-2026:22087-1SUSE-SU-2026:22108-1

Timeline

  1. 24-04-2026
    PublishedVulnerability first disclosed.
  2. 14-06-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix off-by-8 bounds check in check_wsl_eas() The bounds check uses (u8 *)ea + nlen + 1 + vlen as the end of the EA name and value, but ea_data sits at offset sizeof(struct smb2_file_full_ea_info) = 8 from ea, not at offset 0. The strncmp() later reads ea->ea_data[0..nlen-1] and the value bytes follow at ea_data[nlen+1..nlen+vlen], so the actual end is ea->ea_data + nlen + 1 + vlen. Isn't pointer math fun? The earlier check (u8 *)ea > end - sizeof(*ea) only guarantees the 8-byte header is in bounds, but since the last EA is placed within 8 bytes of the end of the response, the name and value bytes are read past the end of iov. Fix this mess all up by using ea->ea_data as the base for the bounds check. An "untrusted" server can use this to leak up to 8 bytes of kernel heap into the EA name comparison and influence which WSL xattr the data is interpreted as.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.13%

Chance of exploitation in the next 30 days

Percentile

2%

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.

Ubuntu160 products
  • linuxAll versions (No fix recorded) | < 7.0.0-27.27
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 7.0.0-1008.8
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Chainguard8 products
  • linux-aws-6.18< 6.18.31-r0
  • linux-azure-6.18< 6.18.31-r0
  • linux-gcp-6.18< 6.18.31-r0
  • linux-qemu-6.12< 6.12.85-r0
  • linux-qemu-6.18< 6.18.31-r0
Linux2 products
  • linux≥ 7449d736bbbd160c76b01b8fcdf72f58a8757d4b, < bfbc74df8bbe095b3ed68f6d4487b368af087890 | ≥ ea41367b2a602f602ea6594fc4a310520dcc64f4, < 5cc0574c84aa73946ade587c41e81757b8b01cb5 | ≥ ea41367b2a602f602ea6594fc4a310520dcc64f4, < b2b76d09a64c538c57006180103fc1841e8cfa66 | ≥ ea41367b2a602f602ea6594fc4a310520dcc64f4, < ba3ad159aa61810bbe0acaf39578b1ebfb6f1a18 | ≥ ea41367b2a602f602ea6594fc4a310520dcc64f4, < a893f1757d9a4009e4a8d7ceb2312142fe29cea4 | ≥ ea41367b2a602f602ea6594fc4a310520dcc64f4, < 3d8b9d06bd3ac4c6846f5498800b0f5f8062e53b | ≥ 6.6.32, < 6.6.136 | 6.9
  • linux_kernel≥ 6.6.32, < 6.6.136 | ≥ 6.9, < 6.12.83 | ≥ 6.13, < 6.18.24 | ≥ 6.19, < 6.19.14 | ≥ 7.0, < 7.0.1
Debian1 product
  • linux< 6.12.85-1 | < 6.19.14-1

4 vendors · 171 products

References

16 links
Show all 16 references