Nokogiri's HTML5 serializer · Nokogiri: Mutation XSS through `noscript` content
Affects MicrosoftSource GCVE Database
Not known to be exploited · CVSS 2.3 Low : upgrade to 1.19.5 when convenient.
Data as of 13 Nov 2026, 10:15 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 4.0 | 2.3 |
|---|
- Patch
- Available – fixed in 1.19.5
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade nokogiri to 1.19.5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| sparklemotionnokogiri | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
A vulnerability identified as CVE-2026-126063 affects Nokogiri's HTML5 serializer, allowing mutation-based cross-site scripting (XSS) through the content of <noscript> elements. This issue is present in version 3.0 of Nokogiri.