Read the docs
TI-2026-74177 Aliases CVE-2026-101927

Heap overflow in Juniper Junos OS eventd enables root escalation

Priority LOW 38CWE-122Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.

Summary

Juniper Networks Junos OS and Junos OS Evolved on all platforms contain a heap-based buffer overflow in the eventd process (CWE-122). An unprivileged local attacker can send crafted IPC event messages to cause a denial of service or escalate privileges to root.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

A Heap-based Buffer Overflow vulnerability in eventd of Juniper Networks Junos OS and Junos OS Evolved on all platforms allows an unprivileged local attacker to cause a denial of service (DoS) or achieve privilege escalation to root via crafted IPC event messages.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00144 3rd percentileScored 2026-11-07
Fix Fixed Junos OS (Juniper Networks): 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5 +4Junos OS Evolved (Juniper Networks): 23.2R2-S7.7-EVO, 23.4R2-S8.11-EVO, 24.2R2-S5.6-EVO +6

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
JuniperJunos OSbefore 23.2R2-S7.7; 23.4 to before 23.4R2-S8.13; 24.2 to before 24.2R2-S5.5; 24.4 to before 24.4R2-S5; 25.2 to before 25.2R2-S2; 25.4 to before 25.4R1-S3; 26.2 to before 26.2R1-S223.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 26.2R1-S2Patch availableCNA
JuniperJunos OS Evolvedbefore 23.2R2-S7.7-EVO; 23.4 to before 23.4R2-S8.11-EVO; 24.2 to before 24.2R2-S5.6-EVO; 24.4 to before 24.4R2-S5-EVO; 25.2 to before 25.2R2-S2-EVO; 25.4 to before 25.4R1-S3-EVO; 26.2 to before 26.2R1-S2-EVO; 23.4X100; 25.2X100 to before 25.2X100-D35-EVO; 25.4X300 to before 25.4X300-D40-EVO23.2R2-S7.7-EVO, 23.4R2-S8.11-EVO, 24.2R2-S5.6-EVO, 24.4R2-S5-EVO, 25.2R2-S2-EVO, 25.4R1-S3-EVO, 26.2R1-S2-EVO, 25.2X100-D35-EVO, 25.4X300-D40-EVOPatch availableCNA
  • Junos OS VendorJuniper Affected before 23.2R2-S7.7; 23.4 to before 23.4R2-S8.13; 24.2 to before 24.2R2-S5.5; 24.4 to before 24.4R2-S5; 25.2 to before 25.2R2-S2; 25.4 to before 25.4R1-S3; 26.2 to before 26.2R1-S2 Fixed in 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 26.2R1-S2 Patch available CNA
  • Junos OS Evolved VendorJuniper Affected before 23.2R2-S7.7-EVO; 23.4 to before 23.4R2-S8.11-EVO; 24.2 to before 24.2R2-S5.6-EVO; 24.4 to before 24.4R2-S5-EVO; 25.2 to before 25.2R2-S2-EVO; 25.4 to before 25.4R1-S3-EVO; 26.2 to before 26.2R1-S2-EVO; 23.4X100; 25.2X100 to before 25.2X100-D35-EVO; 25.4X300 to before 25.4X300-D40-EVO Fixed in 23.2R2-S7.7-EVO, 23.4R2-S8.11-EVO, 24.2R2-S5.6-EVO, 24.4R2-S5-EVO, 25.2R2-S2-EVO, 25.4R1-S3-EVO, 26.2R1-S2-EVO, 25.2X100-D35-EVO, 25.4X300-D40-EVO Patch available CNA

CPE names Threatist (inferred) · 2

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*——Juniper
cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:*——Juniper
  • cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* Versions — — ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:* Versions — — ·Juniper

Remediation

Install a fixed release. For Junos OS, the fixed versions are 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3 and 26.2R1-S2. For Junos OS Evolved, the fixed versions are 23.2R2-S7.7-EVO, 23.4R2-S8.11-EVO, 24.2R2-S5.6-EVO, 24.4R2-S5-EVO, 25.2R2-S2-EVO, 25.4R1-S3-EVO, 26.2R1-S2-EVO, 25.2X100-D35-EVO and 25.4X300-D40-EVO.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA Junos OS (Juniper Networks) Fixed in 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 26.2R1-S2
  • Fix · CNA Junos OS Evolved (Juniper Networks) Fixed in 23.2R2-S7.7-EVO, 23.4R2-S8.11-EVO, 24.2R2-S5.6-EVO, 24.4R2-S5-EVO, 25.2R2-S2-EVO, 25.4R1-S3-EVO, 26.2R1-S2-EVO, 25.2X100-D35-EVO, 25.4X300-D40-EVO

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Juniper Networks Junos OS, Junos OS Evolved — supportportal.juniper.net/JSA112187

    106 records Highest priority Priority MEDIUM 53 MEDIUM, 53 LOW

    Other records, highest priority first

    • TI-2026-74351 Stack overflow in Juniper Junos OS J-Web allows code executionPriority MEDIUM 49
    • TI-2026-74350 Stack-based buffer overflow in Junos OS rpd enables code executionPriority MEDIUM 49
    • TI-2026-74339 Improper authentication in Junos OS J-Web allows device takeoverPriority MEDIUM 49
    Show all 106 records → Advisory →

Timeline

  1. 2026-10-15 Threatist record created from CVE-2026-101927
  2. 2026-10-16 CISA SSVC decision points changed
  3. 2026-10-16 Priority changed: MEDIUM → LOW

References

Advisory 1

  • TI-2023-18638 Junos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to… KEVCVSS 3.1CRITICAL 9.8
  • TI-2020-01585 Out of Cycle Security Advisory: Junos OS: Security vulnerability in J-Web and web based (HTTP/HTTPS) services KEVCVSS 3.1CRITICAL 9.8
  • TI-2015-06436 Juniper ScreenOS 6.2.0r15 through 6.2.0r18, 6.3.0r12 before 6.3.0r12b, 6.3.0r13 before… KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-20885 Apache Commons Text prior to 1.10.0 allows RCE when applied to untrusted input due to insecure interpolation defaults CVSS 3.1CRITICAL 9.8
  • TI-2015-04610 Assertion failure in ISC BIND named via TKEY queries KEVCVSS 3.1HIGH 7.5
  • TI-2025-15550 Junos OS: An local attacker with shell access can execute arbitrary code KEVCVSS 4.0MEDIUM 6.7
See all 1284 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences