Description
re2c 1.3 has a heap-based buffer overflow in Scanner::fill in parse/scanner.cc via a long lexeme.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | re2c | 1.3-2 | — |
| Debian 13 | re2c | 1.3-2 | — |
| Debian 12 | re2c | 1.3-2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | re2c | 1.3-1ubuntu0.1 | USN-4338-2 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | re2c | 1.3-r1 | — |
| Alpine v3.23 | re2c | 1.3-r1 | — |
| Alpine v3.22 | re2c | 1.3-r1 | — |
| Alpine v3.21 | re2c | 1.3-r1 | — |
| Alpine v3.20 | re2c | 1.3-r1 | — |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | re2c | 1.3-r1 | — |
| Alpine v3.18 | re2c | 1.3-r1 | — |
| Alpine v3.17 | re2c | 1.3-r1 | — |
| Alpine v3.16 | re2c | 1.3-r1 | — |
| Alpine v3.15 | re2c | 1.3-r1 | — |
| Alpine v3.14 | re2c | 1.3-r1 | — |
| Alpine v3.13 | re2c | 1.3-r1 | — |
| Alpine v3.12 | re2c | 1.3-r1 | — |
| Alpine v3.11 | re2c | 1.3-r1 | — |
Advisories 1
- USN-4338-2 re2c vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
References
- https://blogs.gentoo.org/ago/2020/04/19/re2c-heap-overflow-in-scannerfill-scanner-cc/
- https://www.openwall.com/lists/oss-security/2020/04/19/1
- https://github.com/skvadrik/re2c/commit/c4603ba5ce229db83a2a4fb93e6d4b4e3ec3776a
- [oss-security] 20200421 Re: re2c: heap overflow in Scanner::fill (scanner.cc) mailing-list
- USN-4338-1 vendor-advisory
- USN-4338-2 vendor-advisory
- GLSA-202007-28 vendor-advisory