Service interruption via unbounded highlight_lines expansion
Published Jun 29, 2026 · Updated Jun 29, 2026
Memory exhaustion in MDEx 0.11.0 through 0.12.2 and MDExNative 0.1.0 through 0.2.2 allows remote attackers to abort a BEAM node. LumisAdapter::parse_highlight_lines eagerly expands attacker-controlled highlight_lines bounds into a Vec with one entry per integer and then performs linear membership scans. Exploitation requires an application to render untrusted Markdown with code-block decorators and inline syntax highlighting enabled; default rendering is unaffected, while successful exploitation interrupts every process on the node.
Summary
What happened
Memory exhaustion in MDEx 0.11.0 through 0.12.2 and MDExNative 0.1.0 through 0.2.2 allows remote attackers to abort a BEAM node. LumisAdapter::parse_highlight_lines eagerly expands attacker-controlled highlight_lines bounds into a Vec with one entry per integer and then performs linear membership scans. Exploitation requires an application to render untrusted Markdown with code-block decorators and inline syntax highlighting enabled; default rendering is unaffected, while successful exploitation interrupts every process on the node.
The record
- CVE
- CVE-2026-53428
- Published
- Jun 29, 2026
- Updated
- Jun 29, 2026
- Vendor
- Leandro Pereira
- Product
- MDExNative
- Classifications
- CWE-789, T1499
- 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 <798a363b4339f6f7162ec8437c4c9f9b5ae6fbf3
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
- Upstream highlight_lines denial-of-service proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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