01 Record
CVE-2026-21920
Junos OS: SRX Series: If a specific request is processed by the DNS subsystem flowd will crash
HighPUBLISHEDCNA: juniper
CNA base score8.7 CVSS v4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/RE:M
02 Description
Junos OS: SRX Series: If a specific request is processed by the DNS subsystem flowd will crash
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.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.47% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 40.9% of scored records. A rank, not a probability.
- NVD base score
- 8.7 (CVSS v4.0), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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:Y/R:A/V:X/RE:M/U:X
- 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 20:28Z9 MO AGO
- Last updated
- 2026-01-15 20:59Z9 MO AGO
- Reserved
- 2026-01-05
- Assigning CNA
- juniper
- Record state
- PUBLISHED
- Severity
- High (CVSS 8.7)
- CNA CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/RE:M
- Weaknesses
- CWE-252Unchecked Return ValueBase
- Data version
- 5.2
- Document digest
- 04007259f4afcfbab03fb4dc8ad2abce91d3d59b6d75ae1e510af9945e3bbca8
05 Affected products
VendorProductVersionsPlatforms
06 References
- supportportal.juniper.nethttps://supportportal.juniper.net/JSA106020
- kb.juniper.nethttps://kb.juniper.net/JSA106020
07 Remediation
The following software releases have been updated to resolve this specific issue: 23.4R2-S5, 24.2R2-S1, 24.4R2, 24.4R2-S1, 25.2R1, and all subsequent releases.