Description
musl libc before 1.1.17 has a buffer overflow via crafted DNS replies because dns_parse_callback in network/lookup_name.c does not restrict the number of addresses, and thus an attacker can provide an unexpected number by sending A records in a reply to an AAAA query.
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 | musl | 1.1.17-1 | — |
| Debian 13 | musl | 1.1.17-1 | — |
| Debian 12 | musl | 1.1.17-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | musl | 1.1.9-1ubuntu0.1~esm2 | USN-4768-1 |
| Ubuntu Pro 14.04 LTS | musl | 0.9.15-1ubuntu0.1~esm1 | USN-4768-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.6 | musl | 1.1.16-r14 | — |
| Alpine v3.5 | musl | 1.1.15-r8 | — |
| Alpine v3.4 | musl | 1.1.14-r16 | — |
| Alpine v3.3 | musl | 1.1.12-r8 | — |
| Alpine v3.2 | musl | 1.1.11-r5 | — |
Advisories 1
- USN-4768-1 musl vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026