CVE-2025-21597
Junos OS and Junos OS Evolved: When BGP rib-sharding and update-threading are configured and a peer flaps, an rpd core is observed
An Improper Check for Unusual or Exceptional Conditions vulnerability in routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer to cause Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, when BGP rib-sharding and update-threading are configured, and a BGP peer flap is done with specific timing, rpd crashes and restarts. Continuous peer flapping at specific time intervals will result in a sustained Denial of Service (DoS) condition.
This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations. This issue requires a remote attacker to have at least one established BGP session. The issue can occur with or without logical-systems enabled.
This issue affects: Junos OS:
-
All versions before 20.4R3-S8,
-
21.2 versions before 21.2R3-S6,
-
21.3 versions before 21.3R3-S5,
-
21.4 versions before 21.4R3-S4,
-
22.1 versions before 22.1R3-S3,
-
22.2 versions before 22.2R3-S1,
-
22.3 versions before 22.3R3,
-
22.4 versions before 22.4R3.
Junos OS Evolved:
- All versions before 21.2R3-S6-EVO,
- 21.3-EVO versions before 21.3R3-S5-EVO,
- 21.4-EVO versions before 21.4R3-S4-EVO,
- 22.1-EVO versions before 22.1R3-S3-EVO,
- 22.2-EVO versions before :22.2R3-S1-EVO,
- 22.3-EVO versions before 22.3R3-EVO,
- 22.4-EVO versions before 22.4R3-EVO.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Junos OS and Junos OS Evolved: When BGP rib-sharding and update-threading are configured and a peer flaps, an rpd core is observed
An Improper Check for Unusual or Exceptional Conditions vulnerability in routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer to cause Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, when BGP rib-sharding and update-threading are configured, and a BGP peer flap is done with specific timing, rpd crashes and restarts. Continuous peer flapping at specific time intervals will result in a sustained Denial of Service (DoS) condition.
This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations. This issue requires a remote attacker to have at least one established BGP session. The issue can occur with or without logical-systems enabled.
This issue affects: Junos OS:
-
All versions before 20.4R3-S8,
-
21.2 versions before 21.2R3-S6,
-
21.3 versions before 21.3R3-S5,
-
21.4 versions before 21.4R3-S4,
-
22.1 versions before 22.1R3-S3,
-
22.2 versions before 22.2R3-S1,
-
22.3 versions before 22.3R3,
-
22.4 versions before 22.4R3.
Junos OS Evolved:
- All versions before 21.2R3-S6-EVO,
- 21.3-EVO versions before 21.3R3-S5-EVO,
- 21.4-EVO versions before 21.4R3-S4-EVO,
- 22.1-EVO versions before 22.1R3-S3-EVO,
- 22.2-EVO versions before :22.2R3-S1-EVO,
- 22.3-EVO versions before 22.3R3-EVO,
- 22.4-EVO versions before 22.4R3-EVO.
- Record
CVE-2025-21597- CVSS 4.0
- 6.0 Medium
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/R:A - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-754
- Updated
- 2026-11-02
EUVDEUVD-2025-10532
An Improper Check for Unusual or Exceptional Conditions vulnerability in routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer to cause Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, when BGP rib-sharding and update-threading are configured, and a BGP peer flap is done with specific timing, rpd crashes and restarts. Continuous peer flapping at specific time intervals will result in a sustained Denial of Service (DoS) condition.
This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations. This issue requires a remote attacker to have at least one established BGP session. The issue can occur with or without logical-systems enabled.
This issue affects: Junos OS:
-
All versions before 20.4R3-S8,
-
21.2 versions before 21.2R3-S6,
-
21.3 versions before 21.3R3-S5,
-
21.4 versions before 21.4R3-S4,
-
22.1 versions before 22.1R3-S3,
-
22.2 versions before 22.2R3-S1,
-
22.3 versions before 22.3R3,
-
22.4 versions before 22.4R3.
Junos OS Evolved:
- All versions before 21.2R3-S6-EVO,
- 21.3-EVO versions before 21.3R3-S5-EVO,
- 21.4-EVO versions before 21.4R3-S4-EVO,
- 22.1-EVO versions before 22.1R3-S3-EVO,
- 22.2-EVO versions before :22.2R3-S1-EVO,
- 22.3-EVO versions before 22.3R3-EVO,
- 22.4-EVO versions before 22.4R3-EVO.
- Record
EUVD-2025-10532- CVSS 4.0
- 6.0 Medium
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/R:A - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-2h84-xh8m-6c6r
An Improper Check for Unusual or Exceptional Conditions vulnerability in routing protocol daemon ...
An Improper Check for Unusual or Exceptional Conditions vulnerability in routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer to cause Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, when BGP rib-sharding and update-threading are configured, and a BGP peer flap is done with specific timing, rpd crashes and restarts. Continuous peer flapping at specific time intervals will result in a sustained Denial of Service (DoS) condition.
This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations. This issue requires a remote attacker to have at least one established BGP session. The issue can occur with or without logical-systems enabled.
This issue affects: Junos OS:
-
All versions before 20.4R3-S8,
-
21.2 versions before 21.2R3-S6,
-
21.3 versions before 21.3R3-S5,
-
21.4 versions before 21.4R3-S4,
-
22.1 versions before 22.1R3-S3,
-
22.2 versions before 22.2R3-S1,
-
22.3 versions before 22.3R3,
-
22.4 versions before 22.4R3.
Junos OS Evolved:
- All versions before 21.2R3-S6-EVO,
- 21.3-EVO versions before 21.3R3-S5-EVO,
- 21.4-EVO versions before 21.4R3-S4-EVO,
- 22.1-EVO versions before 22.1R3-S3-EVO,
- 22.2-EVO versions before :22.2R3-S1-EVO,
- 22.3-EVO versions before 22.3R3-EVO,
- 22.4-EVO versions before 22.4R3-EVO.
- Record
GHSA-2h84-xh8m-6c6r- CVSS 4.0
- 6.0 Medium
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/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:A/V:X/RE:X/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-754
- Updated
- 2026-11-02
NVD
An Improper Check for Unusual or Exceptional Conditions vulnerability in routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer to cause Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, when BGP rib-sharding and update-threading are configured, and a BGP peer flap is done with specific timing, rpd crashes and restarts. Continuous peer flapping at specific time intervals will result in a sustained Denial of Service (DoS) condition.
This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations. This issue requires a remote attacker to have at least one established BGP session. The issue can occur with or without logical-systems enabled.
This issue affects: Junos OS:
-
All versions before 20.4R3-S8,
-
21.2 versions before 21.2R3-S6,
-
21.3 versions before 21.3R3-S5,
-
21.4 versions before 21.4R3-S4,
-
22.1 versions before 22.1R3-S3,
-
22.2 versions before 22.2R3-S1,
-
22.3 versions before 22.3R3,
-
22.4 versions before 22.4R3.
Junos OS Evolved:
- All versions before 21.2R3-S6-EVO,
- 21.3-EVO versions before 21.3R3-S5-EVO,
- 21.4-EVO versions before 21.4R3-S4-EVO,
- 22.1-EVO versions before 22.1R3-S3-EVO,
- 22.2-EVO versions before :22.2R3-S1-EVO,
- 22.3-EVO versions before 22.3R3-EVO,
- 22.4-EVO versions before 22.4R3-EVO.
- Record
CVE-2025-21597- CVSS 4.0
- 6.0 Medium
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/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:A/V:X/RE:X/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-754
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-21597 is a medium vulnerability (CVSS 6.0) in Juniper Junos, published April 9, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 16th percentile. No source names a fixed version.