CVE-2026-101991
MEDIUM 5.3An 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.
NO EXPLOITATION SIGNALS
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 8th percentile
○ In CISA KEV
○ Public exploit / PoC
Impact if exploited
5.3CVSS 4.0 · MEDIUM
- ConfidentialityLow
- IntegrityNone
- AvailabilityNone
What an attacker needs
- ⚠Access: Must sit on the same / adjacent network
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-101991/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-101991/poc.json
Weakness (CWE)
- CWE-130: Improper Handling of Length Parameter Inconsistency
CVSS vector
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
All CVSS metrics
- LOW 3.1 v3.1 · CNA Primary
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N - MEDIUM 5.3 v4.0 · CNA Primary
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - MEDIUM 5.3 v4.0 · NVD Secondary
CVSS: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 3.1 v3.1 · NVD Secondary
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N