Vulnerability in Juniper QFX10000 Series (CVE-2026-57020)
Summary
Vulnerability in Juniper QFX10000 Series (CVE-2026-57020). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on QFX10000 Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).
On all QFX10000 platforms in an EVPN-VxLAN scenario, if an attacker sends IPv6 multicast traffic and these packets reach the non-IRB interface of a spine switch it floods the packet to other spines and all Ethernet Segment Identifier (ESI) leaf switches. This flooding causes the packet to be forwarded in a endless loop, which can lead to saturation of the involved links and in turn impact to legitimate traffic.
This issue affects Junos OS on QFX10000 Series:
- all versions before 23.2R2-S7,
- 23.4 versions before 23.4R2-S8,
- 24.2 versions before 24.2R2-S4,
- 24.4 versions before 24.4R2-S4.
This issue does not affect Junos version after 24.4 as the QFX10000 Series devices are not supported on newer versions anymore.
Source: NIST National Vulnerability Database 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-2026-57020 has been found in Juniper QFX10000 Series.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Juniper QFX10000 Series CVE-2026-57020" on the vendor's site.
CVE-2026-57020 (Juniper QFX10000 Series) — CWE-754 / CVSS v3 6.5
Attack vector: adjacent-network / unauthenticated / no user interaction
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-754) exists in Juniper QFX10000 Series.
Check the vendor advisory for the affected versions of Juniper QFX10000 Series.
Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Juniper QFX10000 Series を使っているサービスとバージョンを洗い出す。
-
2Post-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。
References
- patch sirt@juniper.net
- web nvd.nist.gov
- web github.com