CVE-2025-59964VulnerabilityPublished 9 Oct 2025

CVE-2025-59964: Juniper Networks Junos OS · Use of Uninitialized Resource

Affects Juniper Networks Junos OSSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Juniper Networks Junos OS	Affected =24.4	Fixed in–

AI-suggested

1. Immediate upgrade to Junos OS versions 24.4R1-S3 or 24.4R2 or later where the vulnerability is addressed. 2. If patching is not immediately possible, disable forwarding-options sampling on SRX4700 devices to prevent triggering the vulnerability. 3. Implement network-level filtering to block or rate-limit traffic destined to the Routing Engine (RE) from untrusted sources, reducing exposure to malicious packets. 4. Monitor device logs and performance metrics for signs of FPC crashes or restarts indicative of exploitation attempts. 5. Employ network segmentation to isolate critical Juniper devices from untrusted networks and restrict access to management interfaces. 6. Engage with Juniper support for any available interim mitigation scripts or configuration recommendations. 7. Conduct regular vulnerability assessments and penetration testing focused on network infrastructure devices to detect exploitation attempts early. 8. Maintain an incident response plan tailored to network device DoS scenarios to minimize downtime.

Description

A Use of Uninitialized Resource vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX4700 devices allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). When forwarding-options sampling is enabled, receipt of any traffic destined to the Routing Engine (RE) by the PFE line card leads to an FPC crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of any traffic leading to the RE by the PFE line card will create a sustained Denial of Service (DoS) condition to the PFE line card. This issue affects Junos OS on SRX4700: * from 24.4 before 24.4R1-S3, 24.4R2 This issue affects IPv4 and IPv6.

Impact

For European organizations, especially those operating critical infrastructure, telecommunications, or large enterprise networks using Juniper SRX4700 devices, this vulnerability poses a significant risk to network availability. A successful attack can cause repeated crashes and restarts of the PFE line card, leading to sustained Denial of Service conditions that disrupt traffic forwarding and potentially degrade or halt network services. This can affect business continuity, cause service outages, and impact dependent services such as VPNs, firewalls, and routing functions. Given the vulnerability requires no authentication and can be triggered remotely, attackers can exploit it from outside the network perimeter, increasing the threat surface. The impact is particularly critical for organizations relying on Junos OS 24.4 versions before patched releases. Disruptions in network infrastructure can also have cascading effects on connected systems and services, amplifying operational risks.

CWE-908Use of Uninitialized Resource (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product uses or accesses a resource that has not been initialized.
Implementation
Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
Implementation
Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
Implementation
Avoid race conditions (CWE-362) during initialization routines.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 9 Oct 2025, 16:07 UTC

WeaknessesCWE-908

Technical details

References

Community reviews

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