01 Record
CVE-2026-21908
Junos OS and Junos OS Evolved: Use after free vulnerability In 802.1X authentication daemon can cause crash of the dot1xd process
HighPUBLISHEDCNA: juniper
CNA base score7.5 CVSS v4.0CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/RE:M/U:Green
02 Description
Junos OS and Junos OS Evolved: Use after free vulnerability In 802.1X authentication daemon can cause crash of the dot1xd process
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 0.31% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 23.6% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v4.0), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/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:X/R:X/V:X/RE:M/U:Green
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-06-17.
- 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
- 2026-01-15 20:21Z9 MO AGO
- Last updated
- 2026-02-26 15:04Z8 MO AGO
- Reserved
- 2026-01-05
- Assigning CNA
- juniper
- Record state
- PUBLISHED
- Severity
- High (CVSS 7.5)
- CNA CVSS vector
- CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/RE:M/U:Green
- Weaknesses
- CWE-416Use After FreeVariant
- Data version
- 5.2
- Document digest
- 9ffb1ffdbbb3be011cbcb53e1878b35644a4f301506dca39d9d11d3f1e72bda9
05 Affected products
VendorProductVersionsPlatforms
Juniper NetworksJunos OS23.2R2-S1 to < 23.2R2-S5, 23.4R2 to < 23.4R2-S6, 24.2 to < 24.2R2-S3, 24.4 to < 24.4R2-S1, 25.2 to < 25.2R1-S2, 25.2R2—
Juniper NetworksJunos OS Evolved23.2R2-S1 to < 23.2R2-S5-EVO, 23.4R2 to < 23.4R2-S6-EVO, 24.2 to < 24.2R2-S3-EVO, 24.4 to < 24.4R2-S1-EVO, 25.2 to < 25.2R1-S2-EVO, 25.2R2-EVO—
06 References
- supportportal.juniper.nethttps://supportportal.juniper.net/JSA106007
- kb.juniper.nethttps://kb.juniper.net/JSA106007
07 Remediation
The following software releases have been updated to resolve this specific issue: Junos OS 23.2R2-S5, 23.4R2-S6, 24.2R2-S3, 24.4R2-S1, 25.2R1-S2, 25.2R2, 25.4R1, and all subsequent releases. Junos OS Evolved: 23.2R2-S5-EVO, 23.4R2-S6-EVO, 24.2R2-S3-EVO, 24.4R2-S1-EVO, 25.2R1-S2-EVO, 25.2R2-EVO, 25.4R1-EVO,