CVE-2025-20262
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability in the Protocol Independent Multicast Version 6 (PIM6) feature of Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an authenticated, low-privileged, remote attacker to trigger a crash of the PIM6 process, resulting in a denial of service (DoS) condition. This vulnerability is due to improper processing of PIM6 ephemeral data queries. An attacker could exploit this vulnerability by sending a crafted ephemeral query to an affected device through one of the following methods: NX-API REST, NETCONF, RESTConf, gRPC, or Model Driven Telemetry. A successful exploit could allow the attacker to cause the PIM6 process to crash and restart, causing potential adjacency flaps and resulting in a DoS of the PIM6 and ephemeral query processes.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA vulnerability in the PIM6 feature of Cisco Nexus 3000/9000 Series switches allows an authenticated low-privileged remote attacker to crash the PIM6 process by sending crafted ephemeral data queries via management APIs (NX-API REST, NETCONF, RESTConf, gRPC, or Model Driven Telemetry), causing process restarts and denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the Nexus switch modelRun 'show version' or check the device model to confirm it is a Nexus 3000 or 9000 Series switchAffected if The device is not a Nexus 3000 or 9000 Series switch
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Check the installed software versionRun 'show version' and compare the NX-OS version against the affected version range provided in Cisco's advisory for this CVEAffected if The installed NX-OS version falls within the affected range and has not been patched
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Verify if PIM6 is enabledRun 'show ip pim vrf all' or 'show running-config | include pim' to check if PIM6 (IPv6 PIM) is configured and active on any VRFAffected if PIM6 is enabled and running on the switch
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Confirm management API accessibilityCheck if any of NX-API REST, NETCONF, RESTConf, gRPC, or Model Driven Telemetry are enabled by running 'show feature' or reviewing management interface configurationsAffected if Management APIs are accessible (even from a restricted management network)
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Look for PIM6 process instabilityReview 'show system internal process crashinfo' or check logs for recent PIM6 process crashes or restarts, and run 'show process cpu | include pim6d' to check current process healthAffected if The PIM6 process has recently crashed or is experiencing unexpected restarts
The environment is affected if the device is a Nexus 3000/9000 Series switch running a vulnerable NX-OS version with PIM6 enabled and management APIs accessible, particularly if PIM6 process instability is observed.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply the Cisco patch for this vulnerability when available; until then, restrict management API access to trusted users only and monitor for PIM6 process instability.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2025-20262 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-20262 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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