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Fencer Intel
critical 10.0

CVE-2026-30957 json

OneUptime Synthetic Monitor RCE via exposed Playwright browser object

published 8mo ago modified last mo. also EUVD-2026-10561 , GHSA-jw8q-gjvg-8w4q

cvss
10.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits
0
none known

Summary

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.

Patch / fix

  • npm @oneuptime/common 10.0.21
  • hackerbay oneuptime 10.0.21

Is CVE-2026-30957 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
7mo ago

Exploit prediction

1.30% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/OneUptime/oneuptime/security/advisories/GHSA-jw8q-gjvg-8w4q referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 10.0 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

Affected packages

ecosystem package affected fixed in
npm @oneuptime/common
<10.0.21
10.0.21

Affected products

  • OneUptime oneuptime

Classification

Weakness
  • CWE-749 Exposed Dangerous Method or Function

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.