CVE-2026-48045: Zeroconf is a pure Python implementation of multicast DNS service discovery

Routine

MEDIUM 6.5UPGRADE

CVE-2026-48045 is a medium-severity flaw (CVSS 6.5) affecting zeroconf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.12, AsyncListener.handle_query_or_defer retained every truncated TC-bit incoming query, each up to _MAX_MSG_ABSOLUTE = 8966 bytes, in self._deferred[addr] and armed a per-address timer in self._timers[addr] without capping the per-address list or distinct addr keys, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 69%)
CISA exploited list	No
Weakness	CWE-770
Published	2026-07-17
Last modified	2026-08-17

Publisher (CNA): GitHub, Inc. · Vendor: paulsm

Last updated 2026-08-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-17 19:17 UTCPublished CVE record published
2026-08-17 20:03 UTCUpdated Record last modified

paulsm zeroconf UPGRADE

Affected: < 0.149.12

Fixed in: 0.149.12

Safe to downgrade to: no unaffected older release

1. Check installed version

pip show zeroconf

2. UPGRADE to 0.149.12

pip install --upgrade "zeroconf>=0.149.12"

Verify at the official source NVD · CVE Program · Report a problem with this page
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-2026-48045?

zeroconf: upgrade to 0.149.12. Exact commands for each OS are on this page.

Is CVE-2026-48045 being exploited?

CVE-2026-48045 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-2026-48045 affect?

CVE-2026-48045 affects zeroconf. Severity is medium (CVSS 6.5). Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.12, AsyncListener.handle_query_or_defer retained every truncated TC-bit incoming query, each up to _MAX_MSG_ABSOLUTE = 8966 bytes, in self._deferred

How urgent is CVE-2026-48045?

Priority 30/100. No elevated risk signals yet.

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-48487 MEDIUM 5.3 UPGRADE Zeroconf is a pure Python implementation of multicast DNS service discovery
CVE-2026-47184 MEDIUM 6.5 UPGRADE Zeroconf is a pure Python implementation of multicast DNS service discovery
CVE-2026-47183 MEDIUM 6.5 UPGRADE Zeroconf is a pure Python implementation of multicast DNS service discovery
CVE-2026-47180 MEDIUM 6.5 UPGRADE Zeroconf is a pure Python implementation of multicast DNS service discovery

References

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