CVE-2026-115754 yahoo CVE debrief

Who should care

Defenders responsible for maintaining and securing systems that use the serialize-javascript package should be aware of this vulnerability and take steps to mitigate it. This includes operators, platform administrators, vulnerability management teams, and security teams who need to ensure that the package is updated to a secure version and that any embedded scripts are properly sanitized.

Why it matters

The CVE-2026-115754 vulnerability in serialize-javascript allows for XSS attacks via unescaped </script at the end of serialized function bodies. Defenders should prioritize updating to version 7.1.3 or later and verify embedded script sanitization to prevent potential attacks.

• XSS attacks via crafted JavaScript functions
• Potential for code injection and execution
• Need for input validation and sanitization
• Importance of updating to version 7.1.3 or later

Technical summary

The serialize-javascript package did not properly escape function values whose source ends in a bare </script before version 7.1.3. This could lead to XSS attacks when the serialized output is embedded in a <script> element. The vulnerability is caused by the package's inability to properly escape function values whose source ends in a bare </script. This can lead to XSS attacks when the serialized output is embedded in a <script> element. The issue was fixed in version 7.1.3. Defenders should prioritize updating the serialize-javascript package to version 7.1.3 or later to prevent potential XSS attacks. They should also assess their systems for any usage of vulnerable versions of the package and verify that

Defensive priority

Defenders should prioritize updating the serialize-javascript package to version 7.1.3 or later to prevent potential XSS attacks. They should also assess their systems for any usage of vulnerable versions of the package and verify that any embedded scripts are properly sanitized.

Recommended defensive actions

• Update the serialize-javascript package to version 7.1.3 or later
• Assess systems for usage of vulnerable package versions
• Verify embedded scripts are properly sanitized
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability is caused by the package's inability to properly escape function values whose source ends in a bare </script. This can lead to XSS attacks when the serialized output is embedded in a <script> element. The issue was fixed in version 7.1.3.

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.