How severe is GHSA-xcg2-9pp4-j82x?

GHSA-xcg2-9pp4-j82x has a CVSS score of 5.9/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-xcg2-9pp4-j82x?

GHSA-xcg2-9pp4-j82x affects the following packages: rollbar (npm), rollbar (npm). Ecosystems affected: npm.

How do I fix GHSA-xcg2-9pp4-j82x?

Update rollbar to 2.26.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xcg2-9pp4-j82x is resolved across your whole dependency graph.

How do I detect GHSA-xcg2-9pp4-j82x in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rollbar, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-xcg2-9pp4-j82x if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-xcg2-9pp4-j82x actively exploited in the wild?

No public exploit code has been indexed for GHSA-xcg2-9pp4-j82x yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-xcg2-9pp4-j82x?

GHSA-xcg2-9pp4-j82x has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 34th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-xcg2-9pp4-j82x?

GHSA-xcg2-9pp4-j82x is classified as CWE-1321 (CWE-1321). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-xcg2-9pp4-j82x published, and has it been updated?

GHSA-xcg2-9pp4-j82x was published on October 23, 2025 and was last updated on October 24, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

MEDIUM severity

rollbar vulnerable to Prototype Pollution in merge()GHSA-xcg2-9pp4-j82x

MEDIUMFix: rollbar/rollbar.js#1390

GHSA-xcg2-9pp4-j82x is a medium-severity (CVSS 5.9) CWE-1321 vulnerability in rollbar. A fix is available for rollbar — see the affected versions and patch details below.

Also known asCVE-2025-62517

Published

Oct 23, 2025

Updated

Oct 24, 2025

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-xcg2-9pp4-j82x.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs34th percentile — riskier than 34% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

538other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

rollbarnpm

679Kdownloads / week

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.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`rollbar`	all versions	2.26.5`npm install rollbar@2.26.5`
📦npm	`rollbar`	≥ 3.0.0-alpha1&&< 3.0.0-beta5	3.0.0-beta5`npm install rollbar@3.0.0-beta5`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rollbar, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rollbar to 2.26.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xcg2-9pp4-j82x is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Impact Prototype pollution vulnerability in merge(). If application code calls `rollbar.configure()` with untrusted input, prototype pollution is possible. ### Patches Fixed in 2.26.5 and 3.0.0-beta5. ### Workarounds Ensure that values passed to `rollbar.configure()` do not contain untrusted input. ### References Fixed in https://github.com/rollbar/rollbar.js/pull/1394 (2.26.x) and https://github.com/rollbar/rollbar.js/pull/1390 (3.x)