CVE-2026-33491: zenc · Stack-based Buffer Overflow
Affects zencSource CVE Database V5
Not known to be exploited · CVSS 7.8 High : upgrade to 0.4.4 soon.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.4.4
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 26 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade zenc and zenc-lang/zenc to 0.4.4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| zenc-langzenc | Affected
| Fixed in
|
GitHubzenc-lang/zencpkg:github/zenc-lang/zencOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
To mitigate this vulnerability, organizations should immediately upgrade all instances of the Zen C compiler to version 0.4.4 or later, where the buffer overflow has been fixed. Restrict access to the compiler to trusted users only, and monitor usage to detect any anomalous or unauthorized compilation activities. Implement strict input validation and code review policies for Zen C source files, especially those containing unusually long identifiers. Employ runtime protections such as stack canaries, address space layout randomization (ASLR), and control flow integrity (CFI) in the build environment to reduce exploitation risk. Consider sandboxing the compiler process to limit the impact of potential exploitation. Regularly audit and update development tools and dependencies to ensure vulnerabilities are promptly addressed. Finally, educate developers and system administrators about the risks of processing untrusted source code.
Description
Zen C is a systems programming language that compiles to human-readable GNU C/C11. Prior to version 0.4.4, a stack-based buffer overflow vulnerability in the Zen C compiler allows attackers to cause a compiler crash or potentially execute arbitrary code by providing a specially crafted Zen C source file (`.zc`) with excessively long struct, function, or trait identifiers. Users are advised to update to Zen C version v0.4.4 or later to receive a patch.