CVE-2026-73089 browserslist CVE debrief

Who should care

Defenders responsible for front-end tools and Node.js versions should assess exposure and prioritize updating Browserslist to version 4.28.7 or later. This includes operators, platform administrators, vulnerability management teams, and security teams who manage Browserslist configurations. They should review compensating controls for exposed systems and implement caching mitigations as recommended by the vendor.

Why it matters

CVE-2026-73089 is a high-severity vulnerability in Browserslist that can lead to denial-of-service attacks. Defenders should prioritize updating to version 4.28.7 or later to prevent potential attacks.

• Denial-of-service attacks through memory exhaustion
• Potential for out-of-memory process crashes
• Need for verification of affected versions and exposure
• Priority for updating to version 4.28.7 or later

Technical summary

The Browserslist configuration tool is vulnerable to a denial-of-service attack due to a lack of size cap, TTL, or eviction in its cache and parseCache. An attacker can influence repeated browserslist() query values to cause linear memory growth and an out-of-memory process crash. This issue can be mitigated by updating to version 4.28.7 or later. The vulnerability affects Browserslist configurations and can lead to significant memory consumption, emphasizing the need for defenders to assess exposure and prioritize updates.

Defensive priority

Defenders should prioritize updating Browserslist to version 4.28.7 or later to prevent potential denial-of-service attacks.

Recommended defensive actions

• Update Browserslist to version 4.28.7 or later
• Review and monitor Browserslist usage for potential denial-of-service attacks
• Implement caching mitigations as recommended by the vendor
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score, and references to the fix and affected versions. The vulnerability has a CVSS score of 7.5 and is classified as HIGH severity. The issue was fixed in version 4.28.7 of Browserslist. Defenders should verify affected scope, severity, and vendor guidance through official advisories or CVE records. They should also review compensating controls for exposed systems while remediation is scheduled and verified.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.