CVE-2026-97711: serialize-javascript XSS via script-closing tag bypass in functions

CVE-2026-97711 · Severity: medium · CVSS 4 · Published 2026-09-29

serialize-javascript is a Node.js library that converts JavaScript objects into serialized form. When serializing function values, the library failed to properly neutralize script-closing tags in function source code, allowing attackers to inject HTML and JavaScript that executes in the page origin. An attacker who controls a function passed to serialize-javascript can break out of the script element and execute arbitrary JavaScript in the page.

Technologies: serialize-javascript (npm), Yahoo Serialize-Javascript. Vendors: npm, Yahoo.

Quick answers

Is CVE-2026-97711 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-97711 being exploited in the wild.
How severe is CVE-2026-97711?
Medium severity, with a CVSS score of 4, published 29 September 2026.
Which products and versions are affected?
serialize-javascript (npm) >= 7.1.1, < 7.1.2, SEMVER:introduced=7.1.1,fixed=7.1.2; Yahoo Serialize-Javascript 7.1.1 before 7.1.2.
Is there a fix for CVE-2026-97711?
Yes. serialize-javascript (npm): upgrade to 7.1.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-97711 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-97711?
Check whether you run serialize-javascript (npm) or Yahoo Serialize-Javascript at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • serialize-javascript (npm): upgrade to 7.1.2 or later
    npm install serialize-javascript@7.1.2

Technical details

The vulnerability is a cross-site scripting (XSS) flaw in the function serialization logic. The SCRIPT_CLOSE_REGEXP pattern could match across multiple script-closing tags, causing one tag to be consumed without proper escaping while a second tag survived verbatim. When the serialized output is embedded in an HTML script element, the surviving </script> tag prematurely closes the element, and the remaining payload is parsed as HTML. The vulnerability affects function values only and requires the attacker to supply a malicious function to the serialize() call; ordinary data values are unaffected. Fixed in version 7.1.2.

Affected products

  • Yahoo serialize-javascript 7.1.1 before 7.1.2

Identifiers

  • CVE-2026-97711
  • GHSA-gfhx-hw2g-v5hg

Timeline

  • 2026-09-29: disclosed: CVE-2026-97711 published
  • 2026-09-24: patched: Fix released in version 7.1.2

References

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