Is CVE-2026-48487 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-48487 being exploited in the wild.

How severe is CVE-2026-48487?

Medium severity, with a CVSS score of 6.5, published 17 July 2026.

Which products and versions are affected?

zeroconf (PyPI) < 0.149.16, ECOSYSTEM:introduced=0,fixed=0.149.16; Python-Zeroconf < 0.149.16.

Is there a fix for CVE-2026-48487?

Yes. zeroconf (PyPI): upgrade to 0.149.16 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-48487 attacked?

It is attacked from the adjacent network, in a software library.

Am I affected by CVE-2026-48487?

Check whether you run zeroconf (PyPI) or Python-Zeroconf at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-48487: python-zeroconf cache poisoning via unvalidated RDLENGTH

Q: Which products and versions are affected?

zeroconf (PyPI) < 0.149.16, ECOSYSTEM:introduced=0,fixed=0.149.16; Python-Zeroconf < 0.149.16.

Q: Is there a fix for CVE-2026-48487?

Yes. zeroconf (PyPI): upgrade to 0.149.16 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-48487 attacked?

It is attacked from the adjacent network, in a software library.

Q: Am I affected by CVE-2026-48487?

Check whether you run zeroconf (PyPI) or Python-Zeroconf at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-48487 · Severity: medium · CVSS 6.5 · Published 2026-07-17

Zeroconf is a Python library used by smart home software and other applications to automatically discover devices on a local network. A flaw in how it handles network messages allows an attacker on the same local network to send specially crafted data that corrupts the library's internal cache. This could lead to applications receiving incorrect information about available devices or services, potentially disrupting operations or facilitating further attacks.

Technologies: zeroconf (PyPI), Python-Zeroconf. Vendors: PyPI, Python-Zeroconf.

Quick answers

Is CVE-2026-48487 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-48487 being exploited in the wild.
How severe is CVE-2026-48487?: Medium severity, with a CVSS score of 6.5, published 17 July 2026.
Which products and versions are affected?: zeroconf (PyPI) < 0.149.16, ECOSYSTEM:introduced=0,fixed=0.149.16; Python-Zeroconf < 0.149.16.
Is there a fix for CVE-2026-48487?: Yes. zeroconf (PyPI): upgrade to 0.149.16 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-48487 attacked?: It is attacked from the adjacent network, in a software library.
Am I affected by CVE-2026-48487?: Check whether you run zeroconf (PyPI) or Python-Zeroconf at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

zeroconf (PyPI): upgrade to 0.149.16 or later
```
pip install "zeroconf>=0.149.16"
```

Technical details

A vulnerability exists in the `_read_character_string` and `_read_string` functions within `src/zeroconf/_protocol/incoming.py`. The parser advances the internal data offset by an attacker-declared `RDLENGTH` without verifying it against the actual remaining buffer length (`self._data_len`). Because Python's slicing mechanism silently returns fewer bytes when an index exceeds the buffer, the library constructs and caches truncated TXT, HINFO, or A/AAAA records before a subsequent parse error occurs. This allows unauthenticated adjacent attackers to perform cache poisoning and parser-state desynchronization. The issue is addressed in version 0.149.16 by implementing explicit bounds checks.

Affected products

python-zeroconf zeroconf < 0.149.16

Identifiers

CVE-2026-48487
GHSA-qc2x-6f54-m6h9
PYSEC-2026-3438

Timeline

2026-05-20: patched: Fix merged in PR #1756
2026-05-21: advisory: GHSA-qc2x-6f54-m6h9 published
2026-07-17: disclosed: CVE-2026-48487 published to NVD

References

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