Security readout for executives and security teams
Plain-English summary
Applications using Nokogiri versions before 1.18.3 may crash or potentially allow code execution when they validate specially crafted XML definitions or schemas. Risk is highest where external users or partners can supply DTD or XSD content. The reported severity is critical because exploitation requires no privileges or user interaction under the stated CVSS assumptions.
Executive priority
Treat as an urgent remediation for systems accepting untrusted XML definitions or schemas. Establish exposure immediately and upgrade affected deployments promptly. Systems without these validation paths can follow risk-based scheduling, but version inventory remains necessary because memory corruption can affect availability and potentially confidentiality and integrity.
Technical view
Two libxml2 memory-safety flaws affect Nokogiri before 1.18.3: a stack buffer overflow while reporting DTD validation errors containing long QName prefixes, and a use-after-free during validation against untrusted XML Schemas. Malicious DTD or XSD input may cause denial of service or potentially code execution. CVSS 3.1 is 9.8.
Likely exposure
Exposure requires Nokogiri earlier than 1.18.3 and a workflow that validates attacker-influenced DTD or XSD content. Internet-facing XML ingestion, document-processing services, integrations, and background jobs may qualify. Applications that neither accept nor validate untrusted XML definitions have substantially lower practical exposure. The bundle does not identify specific downstream applications.
Exploitation context
The supplied record is not listed as KEV and provides no evidence of active exploitation. It describes network-reachable, low-complexity exploitation without privileges or user interaction, but actual reachability depends on whether untrusted DTD or XSD validation is exposed. Potential code execution is stated, although denial of service is the more directly established outcome.
Researcher notes
The bundle consistently states that versions before 1.18.3 are vulnerable, although its structured affected-version array is ambiguous and should not be interpreted as a complete range definition. Confirm package resolution and bundled libxml2 behavior against the vendor advisory. No exploit availability, observed attacks, or confirmed code-execution incidents are established by the supplied evidence.
Mitigation direction
- Upgrade Nokogiri to version 1.18.3 or later after compatibility testing.
- Prioritize services that validate externally supplied DTD or XSD content.
- Temporarily reject or isolate untrusted schema and DTD validation where operationally feasible.
- Review the vendor advisory for platform-specific upgrade or deployment guidance.
Validation and detection
- Inventory deployed Nokogiri versions, including transitive dependencies and packaged application images.
- Identify every code path that performs DTD or XML Schema validation.
- Trace whether external users, partners, queues, or stored documents can influence validated content.
- Confirm production artifacts resolve Nokogiri 1.18.3 or later after remediation.
- Monitor XML-processing services for abnormal crashes or memory faults without testing malicious payloads.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-787: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2025-71407 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.3CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- GitHub Security Advisory (GHSA-vvfq-8hwr-qm4m)CVE reference, VulnCheck · vendor-advisory
- VulnCheck Advisory: Nokogiri before 1.18.3 Stack Buffer Overflow and Use-After-FreeCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.