7.1

CVE-2026-46243: smb: client: reject userspace cifs.spnego descriptions

Modified
AliasesRHSA-2026:23258RHSA-2026:23259RHSA-2026:23395
Published 01-06-2026Last modified 15-10-2026

Vulnerability summary

CVE-2026-46243 is a high (CVSS 7.1) Improper Input Validation vulnerability in linux. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 35.6% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Prioritisepublic exploit

Public exploit (GitHub, Date unknown)

Source freshness unavailable

How is this decided?
CVSS score
7.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.41%
0%100%
Low · +0.21 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 226 · Related 211
OPENSUSE-SU-2026:10954-1RHSA-2026:23329RHSA-2026:24381RHSA-2026:25908RHSA-2026:26462RHSA-2026:26515

Showing 100 of 232.

Timeline

  1. 01-06-2026
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.spnego descriptions cifs.spnego key descriptions contain authority-bearing fields such as pid, uid, creduid, and upcall_target that cifs.upcall treats as kernel-originating inputs. However, userspace can also create keys of this type through request_key(2) or add_key(2), allowing those fields to be supplied without CIFS origin. Only accept cifs.spnego descriptions while CIFS is using its private spnego_cred to request the key.

CVSS metrics

6 scores · 5 sources · 2 versions

EPSS trend

Probability

0.41%

Chance of exploitation in the next 30 days

Percentile

36%

Versus all other CVEs

30-day change

Increase +0.21 pp

From 0.20% 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

1 found
  • githubUnverified

    Cifswitch

    Maturity: poc

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.

Ubuntu163 products
  • linux< 3.13.0-214.265 | < 4.4.0-283.317 | < 4.15.0-253.265 | < 5.4.0-233.253 | < 5.15.0-185.195 | < 6.8.0-134.134 | < 6.17.0-40.40 | < 7.0.0-27.27
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.4.0-1156.162 | < 4.4.0-1194.209 | < 4.15.0-1194.207 | < 5.4.0-1161.172 | < 5.15.0-1111.118 | < 6.8.0-1060.63 | < 6.17.0-1019.19 | < 7.0.0-1008.8
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Redhat34 products
  • bpftool< 0:4.18.0-553.129.1.el8_10
  • bpftool-debuginfo< 0:4.18.0-553.129.1.el8_10
  • kernel< 0:4.18.0-553.129.1.el8_10 | < 0:6.12.0-212.9.el10nv
  • kernel-64k< 0:6.12.0-212.9.el10nv
  • kernel-64k-core< 0:6.12.0-212.9.el10nv
Linux2 products
  • linux≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < 7713bd320ed4fc3d08a227cd8e41242219a16981 | ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < 9544559e59438a4b609b2fdfa0763d8360572824 | ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < cf20038657d6d4974349556a34e08fe0490bebbc | ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < 2035acfb17221729b1b8ac335e941868a04ca079 | ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < a3bbda6502a9398b816fa2e71c9a3f955f58013d | ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < 91f89c1d83e80417629791fcef6af8140d7d01c8 | ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < 0aece6685fc80a8de492688ca2315fb86ec379c7 | ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < 3da1fdf4efbc490041eb4f836bf596201203f8f2 | 2.6.24
  • linux_kernel≥ 2.6.24.1, < 5.10.258 | ≥ 5.11, < 5.15.209 | ≥ 5.16, < 6.1.175 | ≥ 6.2, < 6.6.142 | ≥ 6.7, < 6.12.92 | ≥ 6.13, < 6.18.34 | ≥ 6.19, < 7.0.11 | 2.6.24 | 2.6.24:rc3 | 2.6.24:rc4 | 2.6.24:rc5 | 2.6.24:rc6 | 2.6.24:rc7 | 2.6.24:rc8 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4
Debian1 product
  • linux< 6.1.174-1 | < 6.12.90-2 | < 7.0.10-1

4 vendors · 200 products · Showing 200 of 237

References

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