BEAM process crash via recursive Markdown conversion
Published Jun 29, 2026 · Updated Jun 29, 2026
Uncontrolled recursion in MDEx before 0.12.3 and MDExNative before 0.2.3 allows attackers to crash the BEAM via nested Markdown. Mutually recursive Rust AST converters in document.rs traverse attacker-shaped trees without a depth limit, exhausting the native C stack. Any application that renders untrusted Markdown is exposed; the resulting SIGSEGV terminates the entire BEAM node and all processes it hosts.
Summary
What happened
Uncontrolled recursion in MDEx before 0.12.3 and MDExNative before 0.2.3 allows attackers to crash the BEAM via nested Markdown. Mutually recursive Rust AST converters in document.rs traverse attacker-shaped trees without a depth limit, exhausting the native C stack. Any application that renders untrusted Markdown is exposed; the resulting SIGSEGV terminates the entire BEAM node and all processes it hosts.
The record
- CVE
- CVE-2026-54888
- Published
- Jun 29, 2026
- Updated
- Jun 29, 2026
- Vendor
- Leandro Pereira
- Product
- MDExNative
- Classifications
- CWE-674, CAPEC-130, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 29, 2026CVE publishedPublication date reported by the CVE source.
- Jun 29, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0.1.0 <0.2.3
- Affected versionversion=956528c5e31746253347029e810a969ab916fd27 <947696c47bc22bea5dffc0f78c946fa6b70ce183
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-3w4f-53g2-f66p nested-block-quote proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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