CVE-2025-21593: On SRv6 enabled devices, an attacker sending a malformed BGP update can cause the rpd to crash

Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.

Affected and fixed versions

Product / branch	Fixed in
Junos OS 0	21.2R3-S9 or later
Junos OS 21.4	21.4R3-S10 or later
Junos OS 22.2	22.2R3-S5 or later
Junos OS 22.3	22.3R3-S4 or later
Junos OS 22.4	22.4R3-S3 or later
Junos OS 23.2	23.2R2-S2 or later
Junos OS 23.4	23.4R2 or later
Junos OS Evolved 0	21.2R3-S9-EVO or later
Junos OS Evolved 21.4-EVO	21.4R3-S10-EVO or later
Junos OS Evolved 22.2-EVO	22.2R3-S5-EVO or later
Junos OS Evolved 22.3-EVO	22.3R3-S4-EVO or later
Junos OS Evolved 22.4-EVO	22.4R3-S3-EVO or later
Junos OS Evolved 23.2-EVO	23.2R2-S2-EVO or later
Junos OS Evolved 23.4-EVO	23.4R2-EVO or later

Always confirm against the vendor advisory, which lists every fixed hotfix.

What it is

An Improper Control of a Resource Through its Lifetime 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).

On devices with SRv6 (Segment Routing over IPv6) enabled, an attacker can send a malformed BGP UPDATE packet which will cause the rpd to crash and restart. Continued receipt of these UPDATE packets will cause a sustained DoS condition.

This issue affects iBGP and eBGP, and both IPv4 and IPv6 are affected by this vulnerability.This issue affects Junos OS:

All versions before 21.2R3-S9,
from 21.4 before 21.4R3-S10,
from 22.2 before 22.2R3-S5,
from 22.3 before 22.3R3-S4,
from 22.4 before 22.4R3-S3,
from 23.2 before 23.2R2-S2,
from 23.4 before 23.4R2;

and Junos OS Evolved:

All versions before 21.2R3-S9-EVO,
from 21.4-EVO before 21.4R3-S10-EVO,
from 22.2-EVO before 22.2R3-S5-EVO,
from 22.3-EVO before 22.3R3-S4-EVO,
from 22.4-EVO before 22.4R3-S3-EVO,
from 23.2-EVO before 23.2R2-S2-EVO,
from 23.4-EVO before 23.4R2-EVO.

Am I affected?

The configuration required to hit the issue or be potentially exploited is as follows:

[ protocols bgp source-packet-routing srv6 locator ]

Workarounds

There are no known workarounds for this issue.

Exploitation

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.