Prototype Pollution in Rollbar Rollbar.js

CVE-2025-62517

Rollbar.js offers error tracking and logging from Javascript to Rollbar. In versions before 2.26.5 and from 3.0.0-alpha1 to before 3.0.0-beta5, there is a prototype pollution vulnerability in merge(). If application code calls rollbar.configure() with untrusted input, prototype pollution is possible. This issue has been fixed in versions 2.26.5 and 3.0.0-beta5. A workaround involves ensuring that values passed to rollbar.configure() do not contain untrusted input.

Vulnerability class: Prototype Pollution

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (30.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-62517: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-62517?
CVE-2025-62517 is a medium-severity vulnerability in Rollbar Rollbar.js, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 5.9/10. Published 2025-10-23.
How severe is CVE-2025-62517?
Medium severity. CVSS v3 base score is 5.9 out of 10.