How severe is CVE-2026-3089?

No CVSS score has been assigned to CVE-2026-3089 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-3089?

CVE-2026-3089 affects the following packages: @actual-app/sync-server (npm). Ecosystems affected: npm.

How do I fix CVE-2026-3089?

Update @actual-app/sync-server to 26.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-3089 is resolved across your whole dependency graph.

How do I detect CVE-2026-3089 in my npm dependencies?

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

How do I mitigate CVE-2026-3089 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-2026-3089 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-3089 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-2026-3089?

CVE-2026-3089 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 36th 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-2026-3089?

CVE-2026-3089 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-3089 published, and has it been updated?

CVE-2026-3089 was published on March 9, 2026 and was last updated on October 28, 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

CVE-2026-3089 — @actual-app/sync-server

Fix: actualbudget/actual#7067

CVE-2026-3089 is a Path Traversal vulnerability in @actual-app/sync-server. A fix is available for @actual-app/sync-server — see the affected versions and patch details below.

Actual Sync Server 26.2.1 - Authenticated Path Traversal

Also known asGHSA-27vg-33gh-4hwg

Published

Mar 9, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 4, 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.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-3089.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk+0.02%

Lower risk than most CVEs36th percentile — riskier than 36% of all scored CVEsHighest risk

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

Real-World Exposure

1 pkg 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

@actual-app/sync-servernpm

4Kdownloads / week

Description

Actual Sync Server allows authenticated users to upload files through POST /sync/upload-user-file. In versions prior to 26.3.0, improper validation of the user-controlled x-actual-file-id header means that traversal segments (../) can escape the intended directory and write files outside userFiles.

Mitigations

The vulnerability can be mitigated in prior versions by running the sync server in a filesystem sandbox.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@actual-app/sync-server`	all versions	26.3.0`npm install @actual-app/sync-server@26.3.0`

Affected Products

1 product · 1 configurations

Application

actualactualbudget

< 26.3.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @actual-app/sync-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @actual-app/sync-server to 26.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-3089 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

# Description Actual Sync Server allows authenticated users to upload files through `POST /sync/upload-user-file`. In versions prior to 26.3.0, improper validation of the user-controlled `x-actual-file-id` header means that traversal segments (`../`) can escape the intended directory and write files outside `userFiles`. ## Mitigations The vulnerability can be mitigated in prior versions by running the sync server in a filesystem sandbox.

O3 Security · Impact-Aware SCA

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CVE-2026-3089 — @actual-app/sync-server

Exploitation Status

Proof-of-concept exploit code exists

EPSS Exploitation Probability

Real-World Exposure

Description

Description

Mitigations

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2026-3089 in your dependencies?