CVE-2026-86544Network attack vector

Privilege escalation via misclassified code actions

Published Sep 7, 2026 · Updated Sep 9, 2026

Incorrect authorization in Knowns before 0.30.0 allows remote authenticated users to escalate privileges through code.replace. The ActionRegistry omits code.replace, so ClassifyAction falls back to CapRead and the permission guard accepts a file-overwrite operation in read-only sessions. An attacker needs a read-restricted MCP session; overwriting .knowns/config.json takes effect on the next policy check and grants write or delete access.

CVSS severity8.1
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Knowns before 0.30.0 allows remote authenticated users to escalate privileges through code.replace. The ActionRegistry omits code.replace, so ClassifyAction falls back to CapRead and the permission guard accepts a file-overwrite operation in read-only sessions. An attacker needs a read-restricted MCP session; overwriting .knowns/config.json takes effect on the next policy check and grants write or delete access.

The record

CVE
CVE-2026-86544
Published
Sep 7, 2026
Updated
Sep 9, 2026
Vendor
Knowns
Product
Knowns
Classifications
CWE-863, T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.30.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Knowns · Knownsversion=0 <0.30.0

Published CVSS scores

8.1VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
7.2VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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