CVE-2025-52948

Junos OS: Specific unknown traffic pattern causes FPC and system to crash when packet capturing is enabled

MEDIUM
5.9
CVSS Score
Published: July 11, 2025 at 02:40 PM UTC
Updated: June 17, 2026 at 09:37 AM UTC
1 product affected across 1 vendorJunos

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

An Improper Handling of Exceptional Conditions vulnerability in Berkeley Packet Filter (BPF) processing of Juniper Networks Junos OS allows an attacker, in rare cases, sending specific, unknown traffic patterns to cause the FPC and system to crash and restart. BPF provides a raw interface to data link layers in a protocol independent fashion. Internally within the Junos kernel, due to a rare timing issue (race condition), when a BPF instance is cloned, the newly created interface causes an internal structure leakage, leading to a system crash. The precise content and timing of the traffic patterns is indeterminate, but has been seen in a lab environment multiple times. This issue is more likely to occur when packet capturing is enabled.  See required configuration below. This issue affects Junos OS: * all versions before 21.2R3-S9,  * from 21.4 before 21.4R3-S10,  * from 22.2 before 22.2R3-S6,  * from 22.4 before 22.4R3-S7,  * from 23.2 before 23.2R2-S3,  * from 23.4 before 23.4R2-S3,  * from 24.2 before 24.2R1-S1, 24.2R2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Affected range stops below 21.2R3-S9, so it looks safe — our inference, not a vendor statement
Affected range stops below 21.4R3-S10, so it looks safe — our inference, not a vendor statement
Affected range stops below 22.2R3-S6, so it looks safe — our inference, not a vendor statement
Affected range stops below 22.4R3-S7, so it looks safe — our inference, not a vendor statement
Affected range stops below 23.2R2-S3, so it looks safe — our inference, not a vendor statement
Affected range stops below 23.4R2-S3, so it looks safe — our inference, not a vendor statement
Affected range stops below 24.2R1-S1, 24.2R2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMjuniper
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-755

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