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Nokogiri : Possible SSRF on JRuby when resolving external DTDs or entities with `NONET` set

3.7LowCNA
Exploited
No known exploitation
Fix
Fixed in 1.19.5
Who is exposed
Not reported

Do first: Upgrade to a fixed version: 1.19.5.

Published
Last modified
Reference
Last checked
31/100 · provisional
None on Exploit-DB, Metasploit or GitHub

Summary

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.5, on JRuby, applications that parse untrusted XML with DTDLOAD, DTDVALID, or NOENT can have the NONET restriction bypassed when an external DTD or entity uses a short-form IPv4 host or uses absolute paths resolved against a network URL. The resolver can treat these identifiers as local and send a network request, potentially enabling server-side request forgery. CRuby and default parse options are not affected. This issue is fixed in version 1.19.5.

cve.now Index

31Pcve.now Index 31 of 100 · methodology v3 · provisional
  • Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
  • Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Unknown: No advisory context yet
  • Reach10/20Affects RubyGems packages
  • Severity3.7/10CVSS 3.7
  • No patch0/5No signal

What would change the score

  • Would score about 76 if added to CISA KEV
  • Would score about 71 if CISA's SSVC rates exploitation active
  • Would score about 36 if advisories confirm default setups are exposed

What to do

  • Upgrade to a fixed version: 1.19.5.

Check your systems with an agent

Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.

Check whether my systems are affected by CVE-2026-126062 (Nokogiri : Possible SSRF on JRuby when resolving external DTDs or entities with `NONET` set), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-126062 (entry last updated 2026-11-10):
Affected:
- sparklemotion nokogiri: fixed in 1.19.5
- RubyGems package nokogiri: fixed in 1.19.5
Fixed versions: 1.19.5.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-126062 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-126062 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Packages (RubyGems): find every lockfile in each project and run check_stack from the cve.now MCP server on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-v995-44v6-5fqm
- https://github.com/sparklemotion/nokogiri/pull/3752
- https://github.com/sparklemotion/nokogiri/commit/97f41b65f4ee0cac859b87f0b26d2648c4806cb8
- https://github.com/sparklemotion/nokogiri/commit/e448ca2827a9198644610fb730259e12baacdeac
- https://github.com/sparklemotion/nokogiri/releases/tag/v1.19.5
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-126062
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-126062.

Timeline

  1. CVE published
  2. First seen by cve.now

Affected versions

  • sparklemotion nokogiri

    fixed in 1.19.5

  • nokogiriRubyGems

    fixed in 1.19.5

Evidence 7

Vendor advisory · 1

Establishes: Affected and fixed versions.

  1. Advisory

CVE record · 2

Establishes: The identifier and description.

  1. Record
  2. Record

Other links · 4

  1. Repository
  2. Repository
  3. Repository
  4. Repository

Corrections

None so far.

Something wrong on this page? Report an error. Every fix is listed here.

Questions about CVE-2026-126062

Is CVE-2026-126062 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data

Which versions are affected by CVE-2026-126062?

nokogiri: before 1.19.5. nokogiri (RubyGems): before 1.19.5.Source: cve.now feed data

How do I fix CVE-2026-126062?

Upgrade to a fixed version: 1.19.5.Source: cve.now feed data