CVE-2026-55609Public exploit

Arbitrary file access via unrestricted MCP paths

Published Aug 25, 2026 · Updated Aug 26, 2026

Arbitrary file access in rUv sublinear-time-solver before 1.6.0 allows local users to read, write, or overwrite process-accessible files. The export_state, import_state, saveVectorToFile, and loadVectorFromFile MCP tools pass caller-controlled path parameters directly to filesystem reads or writes without confinement or traversal rejection. Exploitation requires permission to invoke an affected MCP tool and is bounded by the server process privileges; overwriting writable application files can interrupt the service.

CVSS severity7.1
High
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file access in rUv sublinear-time-solver before 1.6.0 allows local users to read, write, or overwrite process-accessible files. The export_state, import_state, saveVectorToFile, and loadVectorFromFile MCP tools pass caller-controlled path parameters directly to filesystem reads or writes without confinement or traversal rejection. Exploitation requires permission to invoke an affected MCP tool and is bounded by the server process privileges; overwriting writable application files can interrupt the service.

The record

CVE
CVE-2026-55609
Published
Aug 25, 2026
Updated
Aug 26, 2026
Vendor
ruvnet
Product
sublinear-time-solver
Classifications
CWE-73, T1005, T1565.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 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=< 1.6.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

ruvnet · sublinear-time-solverversion=< 1.6.0

Published CVSS scores

7.1GitHub Security AdvisoryCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-73External Control of File Name or Path
T1005Data from Local System
T1565.001Stored Data Manipulation

Public exploit references

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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