Application object corruption via unfiltered __proto__ merge
Published Oct 23, 2025 · Updated Oct 23, 2025
Prototype pollution in Rollbar.js before 2.26.5 and 3.0.0-alpha1 through 3.0.0-beta4 allows attackers to alter object prototypes. The merge() helper creates a normal result object and recursively copies an untrusted proto property, allowing writes to reach the inherited object prototype. Exploitation requires application code to pass attacker-controlled configuration data to rollbar.configure(), and the demonstrated consequence is unauthorized modification of object properties rather than disclosure or service interruption.
Summary
What happened
Prototype pollution in Rollbar.js before 2.26.5 and 3.0.0-alpha1 through 3.0.0-beta4 allows attackers to alter object prototypes. The merge() helper creates a normal result object and recursively copies an untrusted proto property, allowing writes to reach the inherited object prototype. Exploitation requires application code to pass attacker-controlled configuration data to rollbar.configure(), and the demonstrated consequence is unauthorized modification of object properties rather than disclosure or service interruption.
The record
- CVE
- CVE-2025-62517
- Published
- Oct 23, 2025
- Updated
- Oct 23, 2025
- Vendor
- Rollbar
- Product
- Rollbar.js
- Classifications
- CWE-1321
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 23, 2025CVE publishedPublication date reported by the CVE source.
- Oct 23, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.26.5
- Affected versionversion=>= 3.0.0-alpha1, < 3.0.0-beta5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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