High severity · published Apr 9, 2026
CVE-2026-21916
Junos OS: A low privileged user can escalate their privileges so that they can login as root
7.3
CVSS
0.1%
EPSS
No
On KEV
Description
A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system.
When after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root.
This issue affects Junos OS:
* all versions before 23.2R2-S7,
* 23.4 versions before 23.4R2-S6,
* 24.2 versions before 24.2R2-S3,
* 24.4 versions before 24.4R2-S2,
* 25.2 versions before 25.2R2.
This issue does not affect versions 25.4R1 or later.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
JO
Junos OS · Juniper
before 23.2R2-S7; 23.4 before 23.4R2-S6; 24.2 before 24.2R2-S3; 24.4 before 24.4R2-S2; 25.2 before 25.2R2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-21916
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-21916
Mitigation
https://kb.juniper.net/JSA107807
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