Local application crash via unbounded error formatting
Published Feb 18, 2026 · Updated Feb 18, 2026
Stack-based buffer overflow in Wren 0.4.0 and earlier allows local users to crash an embedding application with crafted Wren source. The compiler's printError function formats an overlong class or method name with unbounded vsprintf into a fixed-size stack buffer. Exploitation requires a host application to compile attacker-controlled Wren code, and the demonstrated consequence is an AddressSanitizer-detected abort.
Summary
What happened
Stack-based buffer overflow in Wren 0.4.0 and earlier allows local users to crash an embedding application with crafted Wren source. The compiler's printError function formats an overlong class or method name with unbounded vsprintf into a fixed-size stack buffer. Exploitation requires a host application to compile attacker-controlled Wren code, and the demonstrated consequence is an AddressSanitizer-detected abort.
The record
- CVE
- CVE-2026-2657
- Published
- Feb 18, 2026
- Updated
- Feb 18, 2026
- Vendor
- wren-lang
- Product
- Wren
- Classifications
- CWE-119, CWE-121
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 18, 2026CVE publishedPublication date reported by the CVE source.
- Feb 18, 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
- Affected versionversion=0.2
- Affected versionversion=0.3
- Affected versionversion=0.4.0
What conditions does exploitation require?
What is affected?
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
- Wren printError stack-overflow reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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