Security Digest · Vulnerability record
CVE-2026-27584: ActualBudget server is Missing Authentication for SimpleFIN and Pluggy AI bank sync endpoints
Actual is a local-first personal finance tool.
CVSS 9.2 Critical EPSS 0.6% · p46
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.6%, percentile 46: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 46% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
@actual-app/sync-server(npm) < 26.2.1, fixed in 26.2.1. Check your lockfile, including transitive dependencies.
What it is
Actual is a local-first personal finance tool. Prior to version 26.2.1, missing authentication middleware in the ActualBudget server component allows any unauthenticated user to query the SimpleFIN and Pluggy.ai integration endpoints and read sensitive bank account balance and transaction information. This vulnerability allows an unauthenticated attacker to read the bank account balance and transaction history of ActualBudget users. This vulnerability impacts all ActualBudget Server users with the SimpleFIN or Pluggy.ai integrations configured. The ActualBudget Server instance must be reachable over the network. Version 26.2.1 patches the issue.
From the GitHub advisory
Summary
Missing authentication middleware in the ActualBudget server component allows any unauthenticated user to query the SimpleFIN and Pluggy.ai integration endpoints and read sensitive bank account balance and transaction information.
Impact
This vulnerability allows an unauthenticated attacker to read the bank account balance and transaction history of ActualBudget users. This vulnerability impacts all ActualBudget Server users with the SimpleFIN or Pluggy.ai integrations configured. The ActualBudget Server instance must be reachable over the network.
Details
Weakness type: CWE-306.
Product: @actual-app/sync-server (npm) · Assigned by: GitHub_M · Published: 2026-02-24
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | @actual-app/sync-server | < 26.2.1 | 26.2.1 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| actualbudget | actual | < 26.2.1 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 4.0 | 9.2 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N |
| GitHub | 4.0 | 9.2 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: none
- Privileges required: none (no login)
- User interaction: none
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable yes, technical impact partial.
- FIRST EPSS (model of 2026-10-21): 0.57% probability of exploitation activity in the next 30 days; percentile 46.
Timeline
- — CVE record published by GitHub_M
- — GitHub-reviewed advisory GHSA-m2cq-xjgm-f668 published (critical)
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-m2cq-xjgm-f668 github.com
- CVE.org record CVE-2026-27584 cve.org
- NVD entry CVE-2026-27584 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com