Answer in brief
CVE-2026-101991 records a Medium severity (CVSS 5.3) vulnerability in Junos OS and Junos OS Evolved: A BGP-LS peer causes heap data disclosure when traffic-engineering routing is enabled. The current sources do not mark it as known exploited. The current feed maps Juniper Networks/Junos OS (generic), Juniper Networks/Junos OS Evolved (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Juniper Networks/Junos OS (generic), Juniper Networks/Junos OS Evolved (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Juniper Networks/Junos OSgeneric | >=0 <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 | 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 26.2R1-S2 |
| Juniper Networks/Junos OS Evolvedgeneric | >=0 <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 | 23.2R2-S7.7-EVO, 23.4R2-S8.11-EVO, 24.2R2-S5.6-EVO, 24.4R2-S5-EVO, 25.2R2-S2-EVO, 25.4R1-S3-EVO, 26.2R1-S2-EVO, 25.2X100-D35-EVO, 25.4X300-D40-EVO |
Published upstream
Oct 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 14, 2026
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.
Quoted source text, attributed separately from HOL analysis.