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01 Record

CVE-2026-21901

Junos OS and Junos OS Evolved: Configuration of a specific SSH option results in mgd crash

MediumPUBLISHEDCNA: juniper
CNA base score6.7 CVSS v4.0CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:Y/R:A/V:D/RE:M/U:Green

02 Description

Junos OS and Junos OS Evolved: Configuration of a specific SSH option results in mgd crash

03 Exploitation and scoring

Exploitation
Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
SSVC decision
  • ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.17% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 7.2% of scored records. A rank, not a probability.
NVD base score
6.7 (CVSS v4.0), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/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:Y/R:A/V:D/RE:M/U:Green
NVD analysis status
Analyzed. NVD last modified this record on 2026-08-26.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-07-09 21:01Z3 MO AGO
Last updated
2026-07-10 14:21Z3 MO AGO
Reserved
2026-01-05
Assigning CNA
juniper
Record state
PUBLISHED
Severity
Medium (CVSS 6.7)
CNA CVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:Y/R:A/V:D/RE:M/U:Green
Weaknesses
  • CWE-476NULL Pointer DereferenceBase
Data version
5.2
Document digest
32c1f6c56798dfb24bb4c756e17e362d5bace194c8852ca23f5a757d99d3d8ab

05 Affected products

VendorProductVersionsPlatforms
Juniper NetworksJunos OS22.3 to < 22.3R3-S5, 22.4 to < 22.4R3-S10, 23.2 to < 23.2R2-S7, 23.4 to < 23.4R2-S8—
Juniper NetworksJunos OS Evolved23.2 to < 23.2R2-S7-EVO, 23.4 to < 23.4R2-S8-EVO—

06 References

07 Remediation

The following software releases have been updated to resolve this specific issue: Junos OS: 22.3R3-S5, 22.4R3-S10, 23.2R2-S7, 23.4R2-S8, 24.2R1, and all subsequent releases. Junos OS Evolved: 23.2R2-S7-EVO, 23.4R2-S8-EVO, 24.2R1-EVO, and all subsequent releases.