Stack buffer overflow in Junos OS MX Series allows root code execution
Key facts
- Attack vector
- 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-121 and the CVSS impact.
Summary
Juniper Junos OS on MX Series is affected in several release lines, including all versions before 21.2R3-S11 and the 21.4, 22.2, 22.3 and 22.4 lines before their listed fixes. A stack-based buffer overflow (CWE-121) in the kmd component lets an unauthenticated network attacker run code as root by sending specific IKE certificate-based packets. The flaw is exploitable only when IKE is enabled with an RSA-signature IKE policy.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
A Stack-based Buffer Overflow vulnerability in the kmd component of Juniper Networks Junos OS on MX Series allows an unauthenticated network attacker to execute code as root via specific IKE certificate-based packets. This issue requires IKE to be enabled with an RSA-signature IKE policy to be vulnerable. This issue affects Junos OS on MX Series: * All versions before 21.2R3-S11; * from 21.4 before 21.4R3-S12; * from 22.2 before 22.2R3-S8; * from 22.3 before 22.3R3-S5; * from 22.4 before 22.4R3-S9;
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
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 | 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 | 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 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
Remediation
Upgrade Junos OS on MX Series to 21.2R3-S11, 21.4R3-S12, 22.2R3-S8, 22.3R3-S5 or 22.4R3-S9 or later within its release line, or to 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3 or 26.2R1-S2 or later. The sources do not list a vendor advisory identifier for this fix.
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/JSA112196
3 records Highest priority Priority MEDIUM 2 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2026-74259 Infinite loop in Junos OS on MX Series allows denial of servicePriority MEDIUM 44
- TI-2026-74276 Junos OS MX rpd reachable assertion allows denial of servicePriority LOW 31
Timeline
- 2026-10-15 Threatist record created from CVE-2026-102182
References
More Juniper vulnerabilities
- 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
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences