How severe is CVE-2026-55609?

CVE-2026-55609 has a CVSS score of 7.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-55609?

CVE-2026-55609 affects the following packages: consciousness-explorer (npm), sublinear-time-solver (npm). Ecosystems affected: npm.

How do I fix CVE-2026-55609?

Update consciousness-explorer to 1.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55609 is resolved across your whole dependency graph.

How do I detect CVE-2026-55609 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for consciousness-explorer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-55609 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2026-55609 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-55609 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-55609?

CVE-2026-55609 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 6th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-55609?

CVE-2026-55609 is classified as CWE-73 (CWE-73). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-55609 published, and has it been updated?

CVE-2026-55609 was published on August 25, 2026 and was last updated on September 11, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

HIGH severity

CVE-2026-55609 — consciousness-explorer

HIGHFix: ruvnet/sublinear-time-solver@a701296

CVE-2026-55609 is a high-severity (CVSS 7.1) CWE-73 vulnerability in consciousness-explorer. A fix is available for consciousness-explorer — see the affected versions and patch details below.

sublinear-time-solver: Arbitrary file write in consciousness-explorer / sublinear-time-solver MCP export_state

Also known asGHSA-xc9g-j69q-37xw

Published

Aug 25, 2026

Updated

Sep 11, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-55609.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs6th percentile — riskier than 6% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-55609 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

consciousness-explorernpm

10downloads / week

sublinear-time-solvernpm

937downloads / week

Description

Impact

An arbitrary file write vulnerability (CWE-73, External Control of File Name or Path) exists in the consciousness-explorer component of sublinear-time-solver. The MCP export_state (and import_state) tool accepted a user-supplied filepath argument and passed it directly to fs.writeFileSync / fs.readFileSync without constraining the destination or rejecting path traversal. An attacker able to invoke the MCP tool could write or overwrite any file accessible to the server process (e.g. ~/.ssh/authorized_keys, application files), leading to integrity loss and potential service disruption.

The same sink class was present in the main solver MCP server (saveVectorToFile / loadVectorFromFile).

Affected versions

consciousness-explorer < 1.1.2
sublinear-time-solver < 1.6.0
sublinear (crates.io) < 0.2.0

Patches

State/vector files are now confined to a dedicated directory (overridable via $CONSCIOUSNESS_EXPLORER_STATE_DIR / $SUBLINEAR_SOLVER_VECTOR_DIR), a basename-only contract is enforced (rejecting separators, .., NUL/control chars, hidden files, and Windows reserved names), and files are opened with O_NOFOLLOW | O_CLOEXEC mode 0o600. Covered by 14 regression tests in tests/consciousness/safe-path.test.mjs.

Breaking change: callers must now pass a basename, not an absolute path.

Workarounds

Do not expose the MCP server to untrusted clients; restrict export_state to trusted local users; run the server under a low-privilege account with a restricted working directory.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`consciousness-explorer`	all versions	1.1.2`npm install consciousness-explorer@1.1.2`
📦npm	`sublinear-time-solver`	all versions	1.6.0`npm install sublinear-time-solver@1.6.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for consciousness-explorer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update consciousness-explorer to 1.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55609 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

### Impact An arbitrary file write vulnerability (CWE-73, External Control of File Name or Path) exists in the `consciousness-explorer` component of `sublinear-time-solver`. The MCP `export_state` (and `import_state`) tool accepted a user-supplied `filepath` argument and passed it directly to `fs.writeFileSync` / `fs.readFileSync` without constraining the destination or rejecting path traversal. An attacker able to invoke the MCP tool could write or overwrite any file accessible to the server process (e.g. `~/.ssh/authorized_keys`, application files), leading to integrity loss and potential se