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TI-2026-74309 Aliases CVE-2026-103994

Heap-based buffer overflow in Junos OS VXLAN Gateway Daemon

Priority MEDIUM 40CWE-122Published · Updated

Key facts

Attack vector
Adjacent network
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 versions before 23.2R2-S7.7, from 23.4 before 23.4R2-S8.13, from 24.2 before 24.2R2-S5.5, from 24.4 before 24.4R2-S5, from 25.2 before 25.2R2-S2, from 25.4 before 25.4R1-S3 and from 26.2 before 26.2R1-S2 are affected. A heap-based buffer overflow (CWE-122) in the VXLAN Gateway Daemon (vgd) lets a malicious or compromised SDN controller crash the OVSDB control plane and possibly execute code remotely.

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

Description from the CNA

A Heap-based Buffer Overflow vulnerability in the VXLAN Gateway Daemon (vgd) of Juniper Networks Junos OS allows a malicious or compromised SDN-controller to cause a complete outage of the OVSDB control plane and possibly remote code execution.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00429 37th percentileScored 2026-11-07
Fix Fixed Junos OS (Juniper Networks): 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5 +4

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
  • 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

CPE names Threatist (inferred) · 1

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:*:*:*:*:*:*:*:* Versions — — ·Juniper

Remediation

Install the fixed Junos OS versions 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.

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

Fixed in the same release

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

  • Advisory ·

    Juniper Networks Junos OS — supportportal.juniper.net/JSA112188

    11 records Highest priority Priority MEDIUM 8 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2026-74194 Improper authentication in Junos OS J-Web allows root command executionPriority MEDIUM 49
    • TI-2026-74283 Reachable assertion in Junos OS TWAMP client disrupts rmopd servicePriority MEDIUM 46
    • TI-2026-74208 Integer underflow in Juniper Junos OS lets attackers crash the kernelPriority MEDIUM 46
    Show all 11 records → Advisory →

Timeline

  1. 2026-10-15 Threatist record created from CVE-2026-103994
  2. 2026-10-16 Priority changed: LOW → MEDIUM

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