Serialize JavaScript serializes JavaScript values to a superset of JSON that includes regular expressions and functions. From 7.1.1 until 7.1.2, function values serialized by serialize-javascript are not fully protected against script-closing tags in attacker-influenced function source because SCRIPT_CLOSE_REGEXP can consume a second closing tag inside one match. When the serialized function is embedded in a script element, the surviving closing tag terminates the element early and causes the remaining output to be parsed as HTML, enabling cross-site scripting in the page origin. Only function values are affected; ordinary data values and options.isJSON output are unaffected. This issue is fixed in version 7.1.2.
https://github.com/yahoo/serialize-javascript/security/advisories/GHSA-gfhx-hw2g-v5hg
https://github.com/yahoo/serialize-javascript/releases/tag/v7.1.2
https://github.com/yahoo/serialize-javascript/commit/2bdbaaff9cb8a4639135eb24cfcd383d3fefb534
Published: 2026-09-29
Updated: 2026-09-30
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 2.3
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Severity: Low
EPSS: 0.003