Vulnerability details

CVE-2026-101955

Juniper Networks Junos OS

Junos OS: SRX Series: Malformed DNS packet causes service disruption when UTM Anti-Spam SBL is used

CVSS 4.0

9.2Critical

Official description

A Stack-based Buffer Overflow vulnerability in the UTM Anti-Spam SBL of Juniper Networks Junos OS on SRX series allows an unauthenticated remote attacker to cause arbitrary code execution or a denial of service via a injected malformed DNS packet when Anti-Spam SBL inspection is enabled.

CVSS scores

Score	Version	Source	Vector
9.2Critical	4.0	CVEProject cvelistV5 (CNA) (juniper)	`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L`
8.1High	3.1	CVEProject cvelistV5 (CNA) (juniper)	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`

Affected products

Vendor	Product	Versions	Source
Juniper Networks	Junos OS	v < 23.2R2-S7.7	CVEProject cvelistV5 (CNA)
Juniper Networks	Junos OS	23.4 ≤ v < 23.4R2-S8.13	CVEProject cvelistV5 (CNA)
Juniper Networks	Junos OS	24.2 ≤ v < 24.2R2-S5.5	CVEProject cvelistV5 (CNA)
Juniper Networks	Junos OS	24.4 ≤ v < 24.4R2-S5	CVEProject cvelistV5 (CNA)
Juniper Networks	Junos OS	25.2 ≤ v < 25.2R2-S2	CVEProject cvelistV5 (CNA)
Juniper Networks	Junos OS	25.4 ≤ v < 25.4R1-S3	CVEProject cvelistV5 (CNA)
Juniper Networks	Junos OS	26.2 ≤ v < 26.2R1-S2	CVEProject cvelistV5 (CNA)

References and advisories

https://supportportal.juniper.net/JSA112186 vendor-advisory

Kolun on Telegram @kolunsec Exploited CVEs, key news and a daily digest Alerts for this product's next CVEsFollow the product to get new vulnerabilities on Telegram.

Details

Published: 2026-10-14
Last updated: 2026-10-16
State: Published
Assigner (CNA): juniper
Kolun priority: 25 · Low

Exploit prediction (EPSS)

0.52%

Probability of exploitation in 30 days

44.9%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: No
Exploitation: None
Technical impact: Total

Weaknesses (CWE)

CWE-121
Stack-based Buffer Overflow