What is CVE-2026-101991?

CVE-2026-101991 is a low-severity vulnerability in Juniper Networks Junos OS, classified under Improper Handling of Length Parameter Inconsistency. CVSS score: 3.1/10. Published 2026-10-14.

How severe is CVE-2026-101991?

Low severity. CVSS v3 base score is 3.1 out of 10.

Vulnerability in Juniper Networks Junos OS

CVE-2026-101991

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.

Published 2026-10-14 · last modified 2026-10-14.

CVSS v3 metric

CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Juniper Networks Junos OS
Juniper Networks Junos OS Evolved — versions 23.4X100

Weakness classification (CWE)

CWE-130 — Improper Handling of Length Parameter Inconsistency

References

supportportal.juniper.net/JSA112187 (vendor-advisory)

Frequently asked questions

What is CVE-2026-101991?: CVE-2026-101991 is a low-severity vulnerability in Juniper Networks Junos OS, classified under Improper Handling of Length Parameter Inconsistency. CVSS score: 3.1/10. Published 2026-10-14.
How severe is CVE-2026-101991?: Low severity. CVSS v3 base score is 3.1 out of 10.