Home/CVE/In the Linux kernel, the following vulnerability has been resolved:
smb: client: reject userspace cifs.spnego descripti
CVE
CVE-2026-46243
In the Linux kernel, the following vulnerability has been resolved:
smb: client: reject userspace cifs.spnego descripti
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.
HIGH · CVSS 7.1
EPSS 0.00021
Act now
- Public exploit or PoC is available
- CVSS base score ≥ 7.0
Sigma rules0
YARA rules0
Look this up elsewhere - one-click external pivots
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How to read a CVE - triage first, then detect and patch
This page is every public fact about CVE-2026-46243, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.
Triage: should I act now? Four signals, and they are not interchangeable:
CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked.
EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal.
CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score.
Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.
How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.
Then what - two workflows:
Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits.
PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.
Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).
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ATT&CK techniques
8Techniques this CVE enables - linked via CWECAPECATT&CK. High◆ = named directly in ATT&CK or Nuclei templates.
T1027 · Obfuscated Files or Information T1036.001 · Invalid Code Signature T1068 · Exploitation for Privilege Escalation T1539 · Steal Web Session Cookie T1553.002 · Code Signing T1562.003 · Impair Command History Logging T1574.006 · Dynamic Linker Hijacking T1574.007 · Path Interception by PATH Environment Variable
▤ Build a SIEM detection for these techniques
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CAPEC attack patterns
12Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.
CAPEC-CAPEC-10 · Buffer Overflow via Environment Variables CAPEC-CAPEC-101 · Server Side Include (SSI) Injection CAPEC-CAPEC-104 · Cross Zone Scripting CAPEC-CAPEC-108 · Command Line Execution through SQL Injection CAPEC-CAPEC-109 · Object Relational Mapping Injection CAPEC-CAPEC-110 · SQL Injection through SOAP Parameter Tampering CAPEC-CAPEC-120 · Double Encoding CAPEC-CAPEC-13 · Subverting Environment Variable Values CAPEC-CAPEC-135 · Format String Injection CAPEC-CAPEC-136 · LDAP Injection CAPEC-CAPEC-14 · Client-side Injection-induced Buffer Overflow CAPEC-CAPEC-153 · Input Data Manipulation
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Weakness Classification
⚠
Public Exploits & PoCs
3These PoC and exploit links come from public sources and are not verified to be safe or functional. Review the code before running anything, and treat unverified entries as untrusted.
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Fixed versions by distribution
80The package version that resolves this CVE on each Linux distribution, from the vendor’s published security data. fixed in shows a patched version exists; open means the package is listed as affected with no fix yet.
oracle allbpftool fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel open
oracle allkernel-abi-stablelists open
oracle allkernel-core fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-cross-headers open
oracle allkernel-debug fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-debug-core open
oracle allkernel-debug-devel fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-debug-modules fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-debug-modules-extra fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-devel fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-headers fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-modules fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-modules-extra fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-tools fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-tools-libs fixed in 0:4.18.0-553.129.1.el8_10
oracle allkernel-tools-libs-devel open
oracle allperf fixed in 0:4.18.0-553.129.1.el8_10
oracle allpython3-perf fixed in 0:4.18.0-553.129.1.el8_10
rhel 8bpftool fixed in 0:4.18.0-553.129.1.el8_10
rhel 8kernel fixed in 0:4.18.0-553.129.1.el8_10
rhel 8kernel-abi-stablelists open
rhel 8kernel-core fixed in 0:4.18.0-553.129.1.el8_10
rhel 8kernel-debug fixed in 0:4.18.0-553.129.1.el8_10
rhel 8kernel-debug-core open
rhel 8kernel-debug-devel fixed in 0:4.18.0-553.129.1.el8_10
rhel 8kernel-debug-modules fixed in 0:4.18.0-553.129.1.el8_10
rhel 8kernel-debug-modules-extra open
rhel 8kernel-devel open
rhel 8kernel-modules open
rhel 8kernel-modules-extra open
rhel 8kernel-rt open
rhel 8kernel-rt-core fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-rt-debug fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-rt-debug-core open
rhel 8kernel-rt-debug-devel fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-rt-debug-kvm fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-rt-debug-modules fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-rt-debug-modules-extra fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-rt-devel fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-rt-kvm fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-rt-modules fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-rt-modules-extra fixed in 0:4.18.0-553.129.1.rt7.470.el8_10
rhel 8kernel-tools open
rhel 8kernel-tools-libs fixed in 0:4.18.0-553.129.1.el8_10
rhel 8kernel-tools-libs-devel open
rhel 8kernel-zfcpdump open
rhel 8kernel-zfcpdump-core open
rhel 8kernel-zfcpdump-devel open
rhel 8kernel-zfcpdump-modules open
rhel 8kernel-zfcpdump-modules-extra open
rhel 8perf open
rhel 8python3-perf open
rhel 9kernel open
rhel 9kernel-64k open
rhel 9kernel-64k-core open
rhel 9kernel-64k-debug open
rhel 9kernel-64k-debug-core fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-64k-debug-devel open
rhel 9kernel-64k-debug-devel-matched open
rhel 9kernel-64k-debug-modules open
rhel 9kernel-64k-debug-modules-core open
rhel 9kernel-64k-debug-modules-extra fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-64k-devel open
rhel 9kernel-64k-devel-matched open
rhel 9kernel-64k-modules fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-64k-modules-core open
rhel 9kernel-64k-modules-extra fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-abi-stablelists open
rhel 9kernel-core fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-debug fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-debug-core fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-debug-devel fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-debug-devel-matched open
rhel 9kernel-debug-modules fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-debug-modules-core open
rhel 9kernel-debug-modules-extra fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-debug-uki-virt fixed in 0:5.14.0-687.13.1.el9_8
rhel 9kernel-devel open
rhel 9kernel-devel-matched open
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Scoring & Timeline
7.1
HIGH · CVSS v3.1 · 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Attack Vector
Network
Adjacent
Local
Physical
Attack Complexity
Low
High
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
SSVC triage · cisa-vulnrichment
Exploitation
poc
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
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Vendor Advisories
14suse-csafSUSE-SU-2026:2383-1
suse-csafSUSE-SU-2026:2331-1
suse-csafSUSE-SU-2026:2332-1
suse-csafSUSE-SU-2026:2310-1
suse-csafSUSE-SU-2026:2317-1
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References & Sources
10Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.