CVE-2026-101991 (CVSS 3.1)

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.

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CVSS v3.1 Score

3.1

LOW

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0019

Probability of exploitation

0.09%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-130 CWE-130

References

Other References

https://supportportal.juniper.net/JSA112187

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 3.1 (LOW).

How severe is CVE-2026-101991? +

CVE-2026-101991 has a CVSS v3.1 score of 3.1 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0019, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-101991? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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