Junos OS Evolved: PTX Series: Receipt of repeated ECMP routing updates results in PFE crash
Priority LOW 36CWE-754Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
An Improper Check for Unusual or Exceptional Conditions vulnerability in the advanced forwarding toolkit (evo-aftmand) of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated network-based attacker generating continuous routing updates, resulting in unilist ECMP routes, to crash the evo-aftmand process on the PFE, leading to a Denial-of-Service (DoS). The conditions required for successful exploitation are based on a sequence of events that are outside an attacker's direct control. Unified list (unilist) ECMP routes are a specific ECMP behavior where multiple equal-cost routes share a single logical next-hop list entry. The router treats them as one route with multiple next hops and load balances traffic across that unified list. Due to an issue processing unilist ECMP routing updates, internal state corruption may occur, especially in large-scale ECMP unilist deployments, leading to the evo-aftmand process crashing, resulting in an evo-aftmand-bx core. Manual intervention is required to recover by rebooting the system or restarting the FPC. This issue affects Junos OS Evolved on PTX : * from 24.4R2-EVO before 24.4R2-S3-EVO; * from 25.2 before 25.2R2-EVO.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00405 35th percentileScored 2026-11-07
Fix Fixed Junos OS Evolved (Juniper Networks): 24.4R2-S3-EVO, 25.2R2, 25.2R2-EVO
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Juniper | Junos OS Evolved | 24.4R2-EVO to before 24.4R2-S3-EVO; 25.2 to before 25.2R2, 25.2R2-EVO | 24.4R2-S3-EVO, 25.2R2, 25.2R2-EVO | Patch available | CNA |
- Junos OS Evolved VendorJuniper Affected 24.4R2-EVO to before 24.4R2-S3-EVO; 25.2 to before 25.2R2, 25.2R2-EVO Fixed in 24.4R2-S3-EVO, 25.2R2, 25.2R2-EVO Patch available CNA
CPE configurations NVD · 25
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:juniper:junos_os_evolved:24.4:r2:*:*:*:*:*:* | 24.4 r2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:24.4:r2-s1:*:*:*:*:*:* | 24.4 r2-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:24.4:r2-s2:*:*:*:*:*:* | 24.4 r2-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:25.2:-:*:*:*:*:*:* | 25.2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:25.2:r1:*:*:*:*:*:* | 25.2 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s1:*:*:*:*:*:* | 25.2 r1-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s2:*:*:*:*:*:* | 25.2 r1-s2 | Vulnerable | Juniper |
| cpe:2.3:h:juniper:ptx1000-72q:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10000:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10001:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
- cpe:2.3:o:juniper:junos_os_evolved:24.4:r2:*:*:*:*:*:* Versions 24.4 r2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos_os_evolved:24.4:r2-s1:*:*:*:*:*:* Versions 24.4 r2-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos_os_evolved:24.4:r2-s2:*:*:*:*:*:* Versions 24.4 r2-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos_os_evolved:25.2:-:*:*:*:*:*:* Versions 25.2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos_os_evolved:25.2:r1:*:*:*:*:*:* Versions 25.2 r1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s1:*:*:*:*:*:* Versions 25.2 r1-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos_os_evolved:25.2:r1-s2:*:*:*:*:*:* Versions 25.2 r1-s2 Vulnerable ·Juniper
- cpe:2.3:h:juniper:ptx1000-72q:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10000:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10001:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
Show 15 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:h:juniper:ptx10001-36mr:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx100016:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10002:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10002-36qdd:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10002-60c:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10003:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10003_160c:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10003_80c:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10003_81cd:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10004:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10008:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx10016:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx12008:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx3000:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ptx5000:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
- cpe:2.3:h:juniper:ptx10001-36mr:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx100016:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10002:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10002-36qdd:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10002-60c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10003:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10003_160c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10003_80c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10003_81cd:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10004:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10008:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx10016:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx12008:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx3000:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ptx5000:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
Remediation
- Fix · CNA Junos OS Evolved (Juniper Networks) Fixed in 24.4R2-S3-EVO, 25.2R2, 25.2R2-EVO
Timeline
- 2026-10-02 Threatist record created from CVE-2026-33794
- 2026-10-03 Alias added: GHSA-978v-9chj-92p2
References
More Juniper Junos Os Evolved vulnerabilities
- TI-2026-17602 Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root CVSS 4.0CRITICAL 9.3
- TI-2026-17601 Junos OS and Junos OS Evolved: Configuration of a specific SSH option results in mgd crash CVSS 4.0MEDIUM 6.7
- TI-2023-04136 Improper input validation in Juniper Junos OS CVSS 3.1HIGH 7.5
- TI-2026-74215 Stack-based buffer overflow in Junos OS rpd triggered by BGP peers CVSS 4.0CRITICAL 9.3
- TI-2026-74211 Authentication bypass in Juniper J-Web allows pre-auth CGI execution CVSS 4.0CRITICAL 9.3
- TI-2021-00146 Junos OS and Junos OS Evolved: Upon receipt of a specific BGP FlowSpec message network traffic may be disrupted. CVSS 3.1CRITICAL 10.0
Sources
- CVE-2026-33794 · CVE Program
- CVE-2026-33794 · NVD
- FIRST EPSS
- GHSA-978v-9chj-92p2 · GitHub Advisory Database · CC BY 4.0
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