PatchTheCVECVE-2018-21232: re2c before 2.0 has uncontrolled recursion that causes stack consumption in find_fixed_tags.
CVE-2018-21232 is a medium-severity flaw (CVSS 5.5) affecting re2c. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
re2c before 2.0 has uncontrolled recursion that causes stack consumption in find_fixed_tags.
Why this priority
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.5 (Medium) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | Required |
| EPSS exploit chance | 1.5% (top 26%) |
| CISA exploited list | No |
| Weakness | CWE-674 |
| Published | 2020-04-29 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2018-21232?
re2c: upgrade to 2.0. Exact commands for each OS are on this page.
Is CVE-2018-21232 being exploited?
CVE-2018-21232 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2018-21232 affect?
CVE-2018-21232 affects re2c. Severity is medium (CVSS 5.5). re2c before 2.0 has uncontrolled recursion that causes stack consumption in find_fixed_tags.
How urgent is CVE-2018-21232?
Priority 43/100. Public exploit reference
Related CVEs
- CVE-2022-23901 CRITICAL 9.8 DOWNGRADE A stack overflow re2c 2.2 exists due to infinite recursion issues in src/dfa/dead_rules.cc.
- CVE-2020-11958 HIGH 7.8 DOWNGRADE MITIGATE re2c 1.3 has a heap-based buffer overflow in Scanner::fill in parse/scanner.cc via a long lexeme.