TI-2026-80918 Aliases CVE-2026-116582 GHSA-9wx9-5pv9-3349

Script injection through RegExp sources in Seroval serialized output

LOW 21CWE-116Published 2026-10-26 · Updated 2026-10-30

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: High
Impact type: Cross-site scripting
Confidentiality · integrity · availability: Low · Low · None
Fix status: Partial Red Hat: 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-79.

Summary

Seroval before 1.0.0 and from 1.5.5 before 1.6.10 serializes RegExp sources that contain a less-than character without the escaping needed inside an HTML script element (CWE-116). An application is affected when it builds regular expression syntax from untrusted input, serializes the result with Seroval's JavaScript-output APIs, and embeds that output in an HTML script element. A crafted source can end the element and run script in the page another user receives.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. Prior to 1.0.0 and from 1.5.5 until 1.6.10, the JavaScript-output APIs serialize a RegExp source containing a less-than character without the escaping needed for an HTML script element. An application is affected when it builds regular expression syntax from untrusted input, serializes that RegExp through serialize, serializeAsync, crossSerialize, crossSerializeAsync, crossSerializeStream, Serializer, or compileJSON, and embeds the result in an HTML script element. The crafted source can terminate the element and execute script in the page received by another user. This issue is fixed in version 1.6.10.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00188 8th percentileScored 2026-11-07

Fix Partial seroval (lxsmnsyc): 1.0.0, 1.6.10seroval (npm): 1.6.10, 1.0.0Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
lxsmnsyc	seroval	before 1.0.0; 1.5.5 to before 1.6.10	1.0.0, 1.6.10	Patch available	CNA
—	seroval (npm)	1.5.5 to before 1.6.10	1.6.10	Patch available	GHSA-9wx9-5pv9-3349
—	seroval (npm)	before 1.0.0	1.0.0	Patch available	GHSA-9wx9-5pv9-3349

seroval Vendorlxsmnsyc Affected before 1.0.0; 1.5.5 to before 1.6.10 Fixed in 1.0.0, 1.6.10 Patch available CNA
seroval (npm) Vendor— Affected 1.5.5 to before 1.6.10 Fixed in 1.6.10 Patch available GHSA-9wx9-5pv9-3349
seroval (npm) Vendor— Affected before 1.0.0 Fixed in 1.0.0 Patch available GHSA-9wx9-5pv9-3349

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:lxsmnsyc:seroval::::::::	—	—	lxsmnsyc

cpe:2.3:a:lxsmnsyc:seroval:*:*:*:*:*:*:*:* Versions — — ·lxsmnsyc

Remediation

Update the npm package seroval to version 1.6.10, or to version 1.0.0 for installs before 1.0.0. Red Hat lists Ansible Automation Orchestrator 2026 as affected, with no plan available.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Fix · CNA seroval (lxsmnsyc) Fixed in 1.0.0, 1.6.10
Fix · GHSA-9wx9-5pv9-3349 seroval (npm) Fixed in 1.6.10 Advisory →
Fix · GHSA-9wx9-5pv9-3349 seroval (npm) Fixed in 1.0.0 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Ansible Automation Orchestrator 2026	Affected	No fix yet: Fix deferred

Timeline

2026-10-26 Threatist record created from CVE-2026-116582
2026-10-27 Affected versions changed · Red Hat
2026-10-27 CVSS score added · Red Hat
2026-10-28 Alias added: GHSA-9wx9-5pv9-3349
2026-10-28 Fix available: npm/[email protected], npm/[email protected] · GHSA-9wx9-5pv9-3349
2026-10-28 CVSS score added · GHSA-9wx9-5pv9-3349
2026-10-28 Weakness changed · GHSA-9wx9-5pv9-3349
2026-10-28 5 new references · GHSA-9wx9-5pv9-3349
2026-10-30 CISA SSVC decision points changed

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-116582

Other 4

TI-2026-42747 Seroval: `seroval.fromJSON()` Promise resolver type confusion invokes attacker-controlled methods during deserialization CVSS 3.1CRITICAL 9.8
TI-2026-66132 Seroval: `fromJSON()` Promise thenable assimilation invokes plugin-produced callables (bypass of CVE-2026-59940) CVSS 3.1CRITICAL 9.8
TI-2026-19109 seroval Affected by Prototype Pollution via JSON Deserialization CVSS 3.1CRITICAL 9.8
TI-2026-19298 seroval affected by Denial of Service via RegExp serialization CVSS 3.1HIGH 7.5
TI-2026-80920 Denial of service in Seroval fromJSON via unvalidated array length CVSS 3.1HIGH 7.5
TI-2026-80917 Seroval fromJSON deserializer hangs on crafted sequence, causing DoS CVSS 3.1HIGH 7.5

See all 12 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences