Vulnerability in zeroconf (CVE-2026-48487)
Summary
Vulnerability in zeroconf (CVE-2026-48487). Data can be tampered with by attackers. Exploitable via _read_character_string. Mitigation: upgrade to 0.149.16 or later.
Original description
The description as published by the source.
Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.16, _read_character_string and _read_string in src/zeroconf/_protocol/incoming.py advanced self.offset by attacker-declared RDLENGTH without checking it against self._data_len, allowing unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb) to send a TXT, HINFO, or A/AAAA record with rdlength=65535 and seed DNSCache and ServiceInfo.properties with truncated, attacker-shaped key/value or address records. This issue is fixed in version 0.149.16.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-48487 has been found in zeroconf.
Attackers can target a specific entry point like _read_character_string over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 5.3/10.
What to do: upgrade zeroconf to 0.149.16 or later.
If unsure, ask your IT team or search "zeroconf CVE-2026-48487" on the vendor's site.
CVE-2026-48487 (zeroconf) — CWE-130 / CVSS v3 5.3
Attack vector: adjacent-network / unauthenticated / no user interaction
Attack surface: _read_character_string / _read_string / self.offset / length
Patched: 0.149.16 — apply immediately
Workaround: There is no in-process workaround; upgrading is the fix.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-130) exists in zeroconf. Attackers reach the vulnerable code path via _read_character_string without authentication.
Check the vendor advisory for the affected versions of zeroconf. Attack surface: _read_character_string / _read_string / self.offset / length.
Severity: Medium (CVSS 5.3/10). Data can be tampered with by attackers.
Update to 0.149.16.
Workaround: There is no in-process workaround; upgrading is the fix.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'zeroconf' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'zeroconf' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
zeroconfを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
There is no in-process workaround; upgrading is the fix.パッチが適用されるまでの応急処置として、There is no in-process workaround; upgrading is the fix. を実施。回避策の副作用 (機能低下) を確認した上で。
-
3Apply patch patch
Upgrade zeroconf to 0.149.16ステージング環境で 0.149.16 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-48487 python-zeroconf
- Ubuntu UBUNTU-CVE-2026-48487 python-zeroconf
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- patch github.com
- report github.com
- web github.com
- web github.com