Description
Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.7, DNSCache._async_add inserted every response record into cache, _expirations, _expire_heap, and service_cache without a cap, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to multicast valid mDNS responses with unique names and cause memory exhaustion, slower cache lookups, slower async_expire passes, and broken discovery, registration, and ServiceBrowser callbacks. This issue is fixed in version 0.149.7.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| python-zeroconf | python-zeroconf | < 0.149.7 | — |
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 | python-zeroconf | 0.149.7-1 | — |
| Debian 13 | python-zeroconf | No fix yet | — |
| Debian 12 | python-zeroconf | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | python-zeroconf | No fix yet | — |
| Ubuntu 24.04 LTS | python-zeroconf | No fix yet | — |
| Ubuntu 22.04 LTS | python-zeroconf | No fix yet | — |
| Ubuntu 20.04 LTS | python-zeroconf | No fix yet | — |
| Ubuntu 18.04 LTS | python-zeroconf | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | python-zeroconf | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | python-zeroconf | 0.136.0-bp160.2.1 | openSUSE-SU-2026:21175-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | zeroconf | < 0.149.7 | 0.149.7 | GHSA-rfg2-pjw2-56x2 |
Advisories 1
- openSUSE-SU-2026:21175-1 Security update for python-zeroconf SUSE / openSUSE Security Updates · Jul 2, 2026
References
- https://github.com/python-zeroconf/python-zeroconf/security/advisories/GHSA-rfg2-pjw2-56x2
- https://github.com/python-zeroconf/python-zeroconf/issues/1715
- https://github.com/python-zeroconf/python-zeroconf/pull/1718
- https://github.com/python-zeroconf/python-zeroconf/commit/0ad3f37b5b852b8f614d322283d148efb2cef6e4
- https://github.com/python-zeroconf/python-zeroconf/releases/tag/0.149.7