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CVE-2026-46243

smb: client: reject userspace cifs.spnego descriptions

No known exploitation. EPSS puts it in the 30th percentile. Fixed versions are out.

CVSS 3.17.1HighEPSS percentile30th0.4% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
No public exploit knownFix5 products4 fixed builds listed below

Published Updated Sources: CVE.org, NVD, BDU, CSAF

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

  • LinuxAffected: ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < 7713bd320ed4fc3d08a227cd8e41242219a16981Upgrade to: 7713bd320ed4fc3d08a227cd8e41242219a16981Affected: ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < 9544559e59438a4b609b2fdfa0763d8360572824Upgrade to: 9544559e59438a4b609b2fdfa0763d8360572824Affected: ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < cf20038657d6d4974349556a34e08fe0490bebbcUpgrade to: cf20038657d6d4974349556a34e08fe0490bebbcAffected: ≥ f1d662a7d5e5322e583aad6b3cfec03d8f27b435, < 2035acfb17221729b1b8ac335e941868a04ca079Upgrade to: 2035acfb17221729b1b8ac335e941868a04ca079 + 4 more branchesStated by: CVE record
  • ООО «РусБИТех-Астра» Astra Linux Special EditionAffected: 1.6 «Смоленск»Upgrade to: not statedStated by: BDU
  • Canonical Ltd. UbuntuAffected: 18.04Upgrade to: not statedStated by: BDU
  • Oracle Corp. Oracle LinuxAffected: 8Upgrade to: not statedStated by: BDU
  • Сообщество свободного программного обеспечения Debian GNU/LinuxAffected: 11Upgrade to: not statedStated by: BDU

Versions as the sources state them. 10 more products have version data. Full version matrix after sign-in

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What it is

From the CVE record

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.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS30th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.4% chance of exploitation activity in the next 30 days, which ranks it in the 30th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

28 events over 136 days, from the signal feeds we watch.

  1. Patch availablerecord updated
  2. Patch availablerecord updated
  3. Patch availablerecord updated
  4. Patch availablerecord updated
  5. Patch availablerecord updated
  6. Patch availablerecord updated

Affected products

And 8 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Scored 7.1 by NVD.

How it is reached

  • Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required LowRequires basic user-level privileges
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability NoneNo availability impact

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

And 542 more references. See all after sign-in

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