CVE-2026-101991: juniper networks junos os
CVSS: 5.3v4.0MediumAwaiting analysis
Published 14-10-2026Last modified 14-10-2026
Vulnerability summary
CVE-2026-101991 is a medium (CVSS 5.3) vulnerability in juniper networks junos os. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8% of scored vulnerabilities.
CVSS score
5.3/10
010
Medium · v4.0 (CVE.org)EPSS score
0.19%
0%100%
Low · Change unavailableKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 14-10-2026PublishedVulnerability first disclosed.
- 14-10-2026Last modifiedVulnerability information updated.
Description
An Improper Handling of Length Parameter Inconsistency vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a configured BGP-LS peer to cause heap data disclosure via a malformed UPDATE sent over a session with the traffic-engineering address family enabled.
CVSS metrics
4 scores · 2 sources · 2 versionsMedium 5.3Preferred score · CVE.org (CNA)
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NSourcesAll 2 agree
- NVDNIST5.3MediumCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/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:X/R:X/V:X/RE:X/U:X
Low 3.1Preferred score · CVE.org (CNA)
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:NSourcesAll 2 agree
- NVDNIST3.1LowCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.19%
Chance of exploitation in the next 30 days
Percentile
8%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
15-10-202620-10-2026
EPSS score0.19%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Juniper networks2 products
- junos os< 23.2R2-S7.7 | ≥ 23.4, < 23.4R2-S8.13 | ≥ 24.2, < 24.2R2-S5.5 | ≥ 24.4, < 24.4R2-S5 | ≥ 25.2, < 25.2R2-S2 | ≥ 25.4, < 25.4R1-S3 | ≥ 26.2, < 26.2R1-S2
- junos os evolved< 23.2R2-S7.7-EVO | ≥ 23.4, < 23.4R2-S8.11-EVO | ≥ 24.2, < 24.2R2-S5.6-EVO | ≥ 24.4, < 24.4R2-S5-EVO | ≥ 25.2, < 25.2R2-S2-EVO | ≥ 25.4, < 25.4R1-S3-EVO | ≥ 26.2, < 26.2R1-S2-EVO | 23.4X100 | ≥ 25.2X100, < 25.2X100-D35-EVO | ≥ 25.4X300, < 25.4X300-D40-EVO
1 vendor · 2 products
References
1 links- supportportal.juniper.net/JSA112187Vendor Advisory