Advisory severityLow3.1Juniper Networks

Low [CVE-2026-101991] Junos OS and Junos OS Evolved: A BGP-LS peer causes heap data disclosure when traffic-engineering routing is enabled

This low-severity Juniper Networks advisory covers CVE-2026-101991 affecting Junos OS, Junos OS Evolved.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.

CVE-2026-101991 Source published Oct 15, 2026Source updated Oct 15, 2026

VulniPulse record published Oct 15, 2026Record updated Oct 15, 2026

CVE-2026-101991

Affected products & platforms

Juniper NetworksJunosJunos OS Evolved

Open source advisory

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Summary

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.

Affected versions

Junos OS before 23.2R2-S7.7
Junos OS 23.4 before 23.4R2-S8.13
Junos OS 24.2 before 24.2R2-S5.5
Junos OS 24.4 before 24.4R2-S5
Junos OS 25.2 before 25.2R2-S2
Junos OS 25.4 before 25.4R1-S3
Junos OS 26.2 before 26.2R1-S2
Junos OS Evolved before 23.2R2-S7.7-EVO
Junos OS Evolved 23.4 before 23.4R2-S8.11-EVO
Junos OS Evolved 24.2 before 24.2R2-S5.6-EVO
Junos OS Evolved 24.4 before 24.4R2-S5-EVO
Junos OS Evolved 25.2 before 25.2R2-S2-EVO

Official advisory · high-confidence parse· fetched 7 days ago·verify at source

Fixed versions

23.2R2-S7.7
23.4R2-S8.13
24.2R2-S5.5
24.4R2-S5
25.2R2-S2
25.4R1-S3
26.2R1-S2
23.2R2-S7.7-EVO
23.4R2-S8.11-EVO
24.2R2-S5.6-EVO
24.4R2-S5-EVO
25.2R2-S2-EVO

Official advisory · high-confidence parse· fetched 7 days ago·verify at source

Mitigation checklist

Recommended fix / mitigation

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.

Official advisory · high-confidence parse· fetched 7 days ago·verify at source

Sources

Official and corroborating records used to build this advisory.

Official vendor advisoryofficial
Official advisory page fetched and parsed; accepted detail fields are attributed to this page.
Juniper Networks
CVE.org CNA recordCVE.org
Independent CNA record used for near-real-time discovery and missed-CVE reconciliation. Discovered from the machine-readable feed https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/delta.json; this link opens the CVE.org record for CVE-2026-101991 instead of the raw feed document.
CVE Program

Cross-references

Validate CVE metadata against the authoritative registries.

CVE-2026-101991NVD CVE.org MITRE

Official resources

Junos OS software downloads & install/upgrade (target: 23.2R2-S7.7 / 23.4R2-S8.13 / 24.2R2-S5.5)
Official documentation
This advisory names 23.2R2-S7.7 / 23.4R2-S8.13 / 24.2R2-S5.5 as the first fixed releases — official upgrade documentation for Junos OS on SRX / MX / EX / QFX.
Junos OS release & EOL / support dates
Release notes
Confirm your train is still supported and pick a fixed maintenance release.
Juniper Security Advisories portal
Official documentation
Canonical Juniper SIRT advisory portal — search here for the full JSA text and revisions.

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