CVE-2026-79772: Unchecked Return Value in sparklemotion nokogiri
Description
Nokogiri versions before 1.19.1 contain a vulnerability where the return value from the xmlC14NExecute function in the canonicalize method is not checked. This causes the method to return an empty string on failure instead of raising an exception. Attackers can exploit this flaw to bypass signature validation in downstream SAML libraries by supplying invalid canonicalized XML that is incorrectly accepted as valid.
CVSS v4.0
Score 6.9medium
Affected software
sparklemotion
nokogiri
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-79772 affects Nokogiri versions prior to 1.19.1. The vulnerability arises because the canonicalize method does not verify the return value of the xmlC14NExecute function. When xmlC14NExecute fails, the method returns an empty string instead of raising an exception, allowing attackers to bypass signature validation in SAML libraries that rely on Nokogiri for XML canonicalization. This can lead to acceptance of tampered or invalid XML signatures.
Potential Impact
The vulnerability allows attackers to bypass signature validation in downstream SAML libraries by providing invalid canonicalized XML that Nokogiri incorrectly accepts as valid. This could undermine the integrity and authenticity guarantees of SAML-based authentication or authorization processes relying on Nokogiri for XML processing.
Mitigation Recommendations
A fix is available in Nokogiri version 1.19.1 and later. Users should upgrade to version 1.19.1 or newer to ensure that the return value from xmlC14NExecute is properly checked and exceptions are raised on failure, preventing signature validation bypass.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-25T14:29:43.528Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a8dba55acd9273b4965b686
Added to database: 08/25/2026, 15:52:53 UTC
Last enriched: 09/10/2026, 18:22:23 UTC
Last updated: 10/09/2026, 18:48:23 UTC
Views: 55
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