BlackTreeIndependent security intelligenceJuniper Networks · Junos OS
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verifiedA Buffer Over-read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). When an affected device receives a BGP update with a set of specific optional transitive attributes over an established peering session, rpd will crash and restart when attempting to advertise the received information to another peer. This issue can only happen if one or both of the BGP peers of the receiving session are non-4-byte-AS capable as determined from the advertised capabilities during BGP session establishment. Junos OS and Junos OS Evolved default behavior is 4-byte-AS capable unless this has been specifically disabled by configuring: [ protocols bgp ... disable-4byte-as ] Established BGP sessions can be checked by executing: show bgp neighbor <IP address> | match "4 byte AS" This issue affects: Junos OS: * all versions before 22.4R3-S8, * 23.2 versions before 23.2R2-S5, * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S2, * 24.4 versions before 24.4R2; Junos OS Evolved: * all versions before 22.4R3-S8-EVO, * 23.2 versions before 23.2R2-S5-EVO, * 23.4 versions before 23.4R2-S6-EVO, * 24.2 versions before 24.2R2-S2-EVO, * 24.4 versions before 24.4R2-EVO.
A Buffer Over-read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). When an affected device receives a BGP update with a set of specific optional transitive attributes over an established peering session, rpd will crash and restart when attempting to advertise the received information to another peer. This issue can only happen if one or both of the BGP peers of the receiving session are non-4-byte-AS capable as determined from the advertised capabilities during BGP session establishment. Junos OS and Junos OS Evolved default behavior is 4-byte-AS capable unless this has been specifically disabled by configuring: [ protocols bgp ... disable-4byte-as ] Established BGP sessions can be checked by executing: show bgp neighbor <IP address> | match "4 byte AS" This issue affects: Junos OS: * all versions before 22.4R3-S8, * 23.2 versions before 23.2R2-S5, * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S2, * 24.4 versions before 24.4R2; Junos OS Evolved: * all versions before 22.4R3-S8-EVO, * 23.2 versions before 23.2R2-S5-EVO, * 23.4 versions before 23.4R2-S6-EVO, * 24.2 versions before 24.2R2-S2-EVO, * 24.4 versions before 24.4R2-EVO.
The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
A Buffer Over-read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). When an affected device receives a BGP update with a set of specific optional transitive attributes over an established peering session, rpd will crash and restart when attempting to advertise the received information to another peer. This issue can only happen if one or both of the BGP peers of the receiving session are non-4-byte-AS capable as determined from the advertised capabilities during BGP session establishment. Junos OS and Junos OS Evolved default behavior is 4-byte-AS capable unless this has been specifically disabled by configuring: [ protocols bgp ... disable-4byte-as ] Established BGP sessions can be checked by executing: show bgp neighbor <IP address> | match "4 byte AS" This issue affects: Junos OS: * all versions before 22.4R3-S8, * 23.2 versions before 23.2R2-S5, * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S2, * 24.4 versions before 24.4R2; Junos OS Evolved: * all versions before 22.4R3-S8-EVO, * 23.2 versions before 23.2R2-S5-EVO, * 23.4 versions before 23.4R2-S6-EVO, * 24.2 versions before 24.2R2-S2-EVO, * 24.4 versions before 24.4R2-EVO.
The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-126: Buffer Over-read. The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/RE:MCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 15 Jan 2026 · Last source change 15 Jan 2026, 21:09 UTC · CWE-126 · Buffer Over-read
Core structured fields are present and their contributing authorities are shown above.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.