Medium · CVSS 4.7CVE-2026-116582

Seroval: Script injection through RegExp sources in serialized outputCVE-2026-116582

Answer in brief

CVE-2026-116582 records a Medium severity (CVSS 4.7) vulnerability in Seroval: Script injection through RegExp sources in serialized output. The current sources do not mark it as known exploited. The current feed maps lxsmnsyc/seroval (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 26, 2026Updated Oct 26, 2026Source checked Oct 26, 2026First seen by HOL Oct 26, 2026Material review Oct 26, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 4.7
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 4.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps lxsmnsyc/seroval (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
lxsmnsyc/serovalgeneric	<1.0.0 \|\| >=1.5.5 <1.6.10	1.0.0, 1.6.10

Recommended response

Check inventory. Check lockfiles and deployed manifests for lxsmnsyc/seroval.
Review the reported fix. Update lxsmnsyc/seroval to 1.0.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 26, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 26, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 26, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.