JunosOperating system · Juniper

CVE-2025-59962

MEDIUM · 5.3 CVSS v3.1 Published 2025-10-09

Fix available

A fix is available. Upgrade to 21.4 / 22.3 or later.

See remediation →

58/100

Remediation priority · Elevated

No privileges Zero-click

Official description

NVD · unedited

An Access of Uninitialized Pointer vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved with BGP sharding configured allows an attacker triggering indirect next-hop updates, along with timing outside the attacker's control, to cause rpd to crash and restart, leading to a Denial of Service (DoS). With BGP sharding enabled, triggering route resolution of an indirect next-hop (e.g., an IGP route change over which a BGP route gets resolved), may cause rpd to crash and restart. An attacker causing continuous IGP route churn, resulting in repeated route re-resolution, will increase the likelihood of triggering this issue, leading to a potentially extended DoS condition. This issue affects: Junos OS: * all versions before 21.4R3-S6, * from 22.1 before 22.1R3-S6, * from 22.2 before 22.2R3-S3, * from 22.3 before 22.3R3-S3, * from 22.4 before 22.4R3, * from 23.2 before 23.2R2; Junos OS Evolved: * all versions before 22.3R3-S3-EVO, * from 22.4 before 22.4R3-EVO, * from 23.2 before 23.2R2-EVO. Versions before Junos OS 21.3R1 and Junos OS Evolved 21.3R1-EVO are unaffected by this issue.

Technical summary

dbcve analysis · high confidence

An uninitialized pointer in the routing protocol daemon (rpd) is accessed when BGP sharding is enabled and indirect next-hop route resolution occurs (e.g., due to IGP route changes). This causes rpd to crash and restart, resulting in denial of service. Repeated IGP route churn increases the likelihood of triggering the crash.

MitigationUpgrade to the fixed Junos OS/Junos OS Evolved versions specified in the advisory. Alternatively, if upgrade is not immediately feasible, consider disabling BGP sharding as a temporary workaround until the upgrade can be performed.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

JunosOperating system

Affected:< 21.4= 21.4= 22.1= 22.2= 22.3= 22.4= 23.2

Junos Os EvolvedOperating system

Affected:< 22.3= 22.3= 22.4= 23.2

CVSS breakdown

From the vector

Attack vector: Adjacent
Complexity: High
Privileges: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected?

dbcve checks

Work through these to decide whether this CVE applies to you.

Check Junos version

Run 'show version' and note the installed Junos OS version

Affected if Version matches < 21.4, = 21.4, = 22.1, = 22.2, = 22.3, = 22.4, or = 23.2 for Junos; or < 22.3, = 22.3, = 22.4, or = 23.2 for Junos OS Evolved
Verify BGP sharding is enabled

Run 'show configuration protocols bgp' and look for the 'sharding' or 'shade' configuration statements under BGP groups

Affected if Output contains 'sharding' or 'shade' configuration under any BGP group
Check for indirect next-hop routes

Run 'show route resolution indirect' and 'show configuration protocols bgp | display set' to inspect next-hop resolution and IGP synchronization settings

Affected if Indirect next-hop resolution is active or BGP is configured to resolve next hops through IGP (e.g., 'resolve-via-igp' or similar)

Environment is affected if running a listed vulnerable Junos version AND BGP sharding is enabled AND indirect next-hop route resolution via IGP is in use, as this combination triggers the uninitialized pointer access in rpd.

Generated from the published advisory. Verify against your own configuration.

Remediation

dbcve · scoped

Upgrade available Upgrade to 21.4 / 22.3 or later

Fixed in 21.422.3

Interim mitigation

Upgrade to the fixed Junos OS/Junos OS Evolved versions specified in the advisory. Alternatively, if upgrade is not immediately feasible, consider disabling BGP sharding as a temporary workaround until the upgrade can be performed.

Recommended fix High confidence

Junos OS: 21.4R3-S6, 22.1R3-S6, 22.2R3-S3, 22.3R3-S3, 22.4R3, or 23.2R2 (or later); Junos OS Evolved: 22.3R3-S3-EVO, 22.4R3-EVO, or 23.2R2-EVO (or later)

1. Identify the exact Junos OS or Junos OS Evolved version currently running on the affected device using 'show version' command.
2. Confirm whether BGP sharding is enabled on the device using 'show bgp sharding' or reviewing the configuration under 'protocols bgp' hierarchy.
3. Based on the current version, determine the minimum fixed release required: For Junos OS 21.4x versions, upgrade to 21.4R3-S6 or later; For 22.1x versions, upgrade to 22.1R3-S6 or later; For 22.2x versions, upgrade to 22.2R3-S3 or later; For 22.3x versions, upgrade to 22.3R3-S3 or later; For 22.4x versions, upgrade to 22.4R3 or later; For 23.2x versions, upgrade to 23.2R2 or later.
4. For Junos OS Evolved: For 22.3x versions, upgrade to 22.3R3-S3-EVO or later; For 22.4x versions, upgrade to 22.4R3-EVO or later; For 23.2x versions, upgrade to 23.2R2-EVO or later.
5. Download the appropriate upgrade package from the Juniper Networks support portal (supportportal.juniper.net).
6. Upload the upgrade package to the device using 'file copy' or via the management interface.
7. Install the upgrade using 'request system software add <package-name>' command.
8. After installation, reboot the device using 'request system reboot' command.

Caveat Standard Junos upgrade precautions apply - verify hardware compatibility, review release notes for known issues, and plan maintenance window as upgrade will require system reboot

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Junos Scoped from the published advisory

Consultation8.0 h
Implementation12.0 h
Testing8.0 h
Review / QA4.0 h

32.0 hours of engineering $5,680

Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,088.

Scan for this in your stack

Free · runs locally

dbcve dependency scanner

Check whether your project pulls in CVE-2025-59962 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References

Primary sources

supportportal.juniper.netVendor Advisory
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-59962 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2025-59962?

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

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here

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
No spam, self-promotion, credentials, or personal data

At a glance

A fix existsUpgrade to 21.4 / 22.3 or later

Severity 5.3 Medium

Exploit likelihood EPSS, next 30 days 0.2%

Affects: Junos

Remediation

Need this fixed?

Fix this in Junos 32 hrs · Moderate

Typical engagement from $5,680

Get a fix See the full breakdown ↓

We specialise in CVE remediation. Send your environment and we’ll scope CVE-2025-59962 and return a fixed quote.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

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.

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.

Check your environment

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.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References