5.3

CVE-2026-57436: nokogiri Use After Free

CVSS: 5.3v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-57436DEBIAN-CVE-2026-57436GHSA-wjv4-x9w8-wm3h
Published 25-06-2026Last modified 25-06-2026
Open JSON

Vulnerability summary

CVE-2026-57436 is a medium (CVSS 5.3) Use After Free vulnerability in nokogiri. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 33.2% of scored vulnerabilities.

Overall risk
21/100
0100
Low · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v3.1 (NVD)
EPSS score
0.40%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 25-06-2026
    PublishedVulnerability first disclosed.
  2. 25-06-2026
    Last modifiedVulnerability information updated.

Description

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri::XML::Document#root= validated only that the new root was a Nokogiri::XML::Node, allowing a DTD node to be set as the document root. The result is a heap use-after-free during garbage collection or finalization, leading to an invalid memory read or potentially a segfault. This vulnerability is fixed in 1.19.4.

CVSS metrics

7 scores · 5 sources · 2 versions

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

0.00 pp

From 0.40% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.40%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • ruby-nokogiriAll versions (No fix recorded) | < 1.19.4+dfsg-1
Nokogiri1 product
RubyGems1 product
  • nokogiri< 1.19.4
Sparklemotion1 product
Ubuntu1 product
  • ruby-nokogiriAll versions (No fix recorded)

5 vendors · 5 products

References

6 links