Security readout for executives and security teams
Plain-English summary
CVE-2023-37463 affects GitHub’s cmark-gfm Markdown parser. Certain Markdown inputs can make vulnerable versions consume excessive resources, potentially causing denial of service. The issue is patched in 0.29.0.gfm.12. Business urgency is moderate: prioritize systems that render user-supplied Markdown.
Executive priority
Treat as a moderate availability risk. Remediate during the next standard security update cycle, faster for internet-facing or multi-tenant Markdown rendering services.
Technical view
cmark-gfm versions before 0.29.0.gfm.12 contain three polynomial-time complexity flaws categorized as CWE-400. The CVSS 3.1 score is 6.4, with network attack vector, low privileges required, high attack complexity, and high availability impact. The source bundle does not provide exploit payloads or deeper root-cause detail.
Likely exposure
Exposure is most likely where cmark-gfm is embedded in applications or services that process Markdown, especially user-submitted Markdown. Confirm direct and transitive dependencies below 0.29.0.gfm.12.
Exploitation context
The bundle does not show CISA KEV listing or active exploitation evidence. The advisory indicates denial-of-service risk through resource exhaustion, with low privileges required and high attack complexity in the CVSS vector.
Researcher notes
Evidence is limited to the advisory-level description: three polynomial complexity issues causing potential unbounded resource exhaustion. Avoid assuming affected downstream products unless dependency evidence confirms cmark-gfm below 0.29.0.gfm.12.
Mitigation direction
- Upgrade cmark-gfm to 0.29.0.gfm.12 or later.
- Update applications or packages that embed vulnerable cmark-gfm versions.
- Prioritize services rendering untrusted or user-supplied Markdown.
- Check the GitHub advisory and release notes for vendor guidance.
- Redeploy rebuilt services after dependency updates.
Validation and detection
- Inventory direct and transitive uses of cmark-gfm.
- Confirm deployed versions are 0.29.0.gfm.12 or later.
- Identify public or authenticated Markdown-rendering workflows.
- Review SBOMs, lockfiles, and container images for vulnerable versions.
- Verify production deployments use the rebuilt dependency.
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-400: 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 lookupCVE-2023-37463 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
- Medium
- CVSS
- 6.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/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.
CVSS vector scores
1 official scoreWe 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:H/PR:L/UI:N/S:U/C:L/I:L/A:H1.64.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.4MediumVector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/github/cmark-gfm/security/advisories/GHSA-w4qg-3vf7-m9x5CVE reference · x_refsource_CONFIRM
- https://github.com/github/cmark-gfm/releases/tag/0.29.0.gfm.12CVE reference · x_refsource_MISC
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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.