Local process crash via off-by-one null termination
Published Feb 13, 2026 · Updated Feb 13, 2026
Stack-based overflow in BACnet Stack 1.4.2 and earlier or 1.5.0.rc1 through 1.5.0.rc2 allows local users to crash ubasic. tokenizer_string caps a string at the full 40-byte destination length, copies those bytes, then writes the terminator to out-of-bounds dest[40]. A user must cause an application embedding the interpreter to process an overlength string literal; the demonstrated consequence is a SIGABRT process crash, with no reported data disclosure or modification.
Summary
What happened
Stack-based overflow in BACnet Stack 1.4.2 and earlier or 1.5.0.rc1 through 1.5.0.rc2 allows local users to crash ubasic. tokenizer_string caps a string at the full 40-byte destination length, copies those bytes, then writes the terminator to out-of-bounds dest[40]. A user must cause an application embedding the interpreter to process an overlength string literal; the demonstrated consequence is a SIGABRT process crash, with no reported data disclosure or modification.
The record
- CVE
- CVE-2026-21870
- Published
- Feb 13, 2026
- Updated
- Feb 13, 2026
- Vendor
- BACnet Stack
- Product
- BACnet Stack
- Classifications
- CWE-193
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 13, 2026CVE publishedPublication date reported by the CVE source.
- Feb 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=<= 1.4.2
- Affected versionversion=>= 1.5.0.rc1, <= 1.5.0.rc2
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-pc83-wp6w-93mx ubasic crash 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
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo