Security Digest · Vulnerability record
CVE-2026-30957: OneUptime has Synthetic Monitor RCE via exposed Playwright browser object
OneUptime is a solution for monitoring and managing online services.
CVSS 10.0 Critical EPSS 1.2% · p68
Should you act?
Critical, preconditions apply
Severe if exploited, but exploitation needs conditions that may not apply to you. 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 1.2%, percentile 68: FIRST’s model estimates a 1.2% chance of exploitation activity in the next 30 days, higher than 68% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes
@oneuptime/common(npm) < 10.0.21, fixed in 10.0.21. Check your lockfile, including transitive dependencies.
What it is
OneUptime is a solution for monitoring and managing online services. Prior to 10.0.21, OneUptime Synthetic Monitors allow a low-privileged authenticated project user to execute arbitrary commands on the oneuptime-probe server/container. The root cause is that untrusted Synthetic Monitor code is executed inside Node's vm while live host-realm Playwright browser and page objects are exposed to it. A malicious user can call Playwright APIs on the injected browser object and cause the probe to spawn an attacker-controlled executable. This is a server-side remote code execution issue. It does not require a separate vm sandbox escape. This vulnerability is fixed in 10.0.21.
From the GitHub advisory
Summary
OneUptime Synthetic Monitors allow a low-privileged authenticated project user to execute arbitrary commands on the oneuptime-probe server/container.
The root cause is that untrusted Synthetic Monitor code is executed inside Node's vm while live host-realm Playwright browser and page objects are exposed to it. A malicious user can call Playwright APIs on the injected browser object and cause the probe to spawn an attacker-controlled executable.
This is a server-side remote code execution issue. It does not require a separate vm sandbox escape.
Details
Weakness type: CWE-749.
Product: @oneuptime/common (npm) · Assigned by: GitHub_M · Published: 2026-03-10
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | @oneuptime/common | < 10.0.21 | 10.0.21 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| OneUptime | oneuptime | < 10.0.21 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 3.1 | 10 Critical | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: low (any account)
- User interaction: none
- Scope: changed (can affect other components)
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 no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 1.20% probability of exploitation activity in the next 30 days; percentile 68.
Timeline
- — CVE record last updated
- — CVE record published by GitHub_M
- — GitHub-reviewed advisory GHSA-jw8q-gjvg-8w4q published (critical)
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-jw8q-gjvg-8w4q github.com
- CVE.org record CVE-2026-30957 cve.org
- NVD entry CVE-2026-30957 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com