Cyber Resilience

CVE-2025-59958

Juniper Junos Os Evolved ≤ 22.4

Published
09 October 2025
Modified
23 January 2026
Patch / advisory
CVSS Score v4 6.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:M/U:X
EPSS Score 0.0026 18th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-59958 is a medium-severity Improper Check for Unusual or Exceptional Conditions (CWE-754) vulnerability in Juniper Junos Os Evolved. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Denial of Service (T1498); ranked at the 18th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to cause impact to confidentiality and availability. When an output firewall…

more

filter is configured with one or more terms where the action is 'reject', packets matching these terms are erroneously sent to the Routing Engine (RE) and further processed there. Processing of these packets will consume limited RE resources. Also responses from the RE back to the source of this traffic could reveal confidential information about the affected device. This issue only applies to firewall filters applied to WAN or revenue interfaces, so not the mgmt or lo0 interface of the routing-engine, nor any input filters. This issue affects Junos OS Evolved on PTX Series: * all versions before 22.4R3-EVO, * 23.2 versions before 23.2R2-EVO.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1498 Network Denial of Service Impact
Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Vulnerability directly enables network-based resource exhaustion on the Routing Engine (T1498/T1499.004) via erroneous packet forwarding from PFE when output reject filters are hit on WAN interfaces; responses may also leak device information.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-33794Same product: Juniper Junos Os Evolved
CVE-2026-57022Same vendor: Juniper
CVE-2025-60004Same product: Juniper Junos Os Evolved
CVE-2025-60011Same product: Juniper Junos Os Evolved
CVE-2024-21614Same product: Juniper Junos Os Evolved
CVE-2026-33801Same product: Juniper Junos Os Evolved
CVE-2026-33781Same vendor: Juniper
CVE-2026-33790Same vendor: Juniper
CVE-2026-21910Same vendor: Juniper
CVE-2026-33783Same product: Juniper Junos Os Evolved

Affected Assets

juniper
junos os evolved
22.4, 23.2 · ≤ 22.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-4 Information Flow Enforcement
  • SC-7 Boundary Protection
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces the intended 'reject' action of output firewall filters at the PFE so that matching packets are dropped rather than punted to the RE.

prevent

Enforces information-flow policy defined by the firewall filter terms, preventing the erroneous forwarding of rejected packets to the control plane.

prevent

Requires boundary-protection mechanisms (WAN-interface filters) to be correctly implemented in the forwarding plane rather than leaking traffic or state to the RE.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly require proper checks and handling for exceptional conditions throughout the SDLC.

DE.CM-09 partial match
prevents

Runtime monitoring of software and environments can detect adverse events triggered by unhandled exceptional conditions.

PR.PS-04 partial match
prevents

Generating logs of exceptions and errors enables detection of improper handling of unusual conditions.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development and acceptance verifies handling of error and exceptional conditions.

A.8.15 Logging partial match
detects

Logging can record unhandled exceptions but does not prevent the weakness itself.

detects

Monitoring may detect symptoms of unhandled conditions but does not eliminate the root weakness.

prevents

Secure development life cycle mandates exception handling and input validation that directly prevent missing checks for unusual conditions.

prevents

Application security requirements explicitly call for handling of exceptional conditions and error paths.

prevents

Secure system architecture and engineering principles require robust error and exception handling mechanisms.

Hardening callouts derived

Configuration rules from DISA STIG baselines that reduce the attack surface for weaknesses of the type cited by this CVE. Derived transitively via CVE→CWE→STIG over `controls_xwalks` (authoritative rows only).

Oracle Linux 8 (2 rules)
  • V-248573 The OL 8 file integrity tool must notify the system administrator (SA) when changes to the baseline configuration or anomalies in the operation of any security functions are discovered within an organizationally defined frequency. via CWE-754
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-754
Oracle Linux 9 (1 rule)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. via CWE-754

References