Junos OS: NULL Pointer Dereference
CVE-2026-101948 is a high-severity NULL pointer dereference vulnerability in Junos OS from Juniper Networks, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 25.2R2-S2, 25.4R1-S3, 26.2R1-S2 as the first without the flaw, so updating Junos OS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.46% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS to 25.2R2-S2 or 25.4R1-S3 or 26.2R1-S2, whichever matches your release line, or a later version.
- Update Junos OS Evolved to 25.2R2-S2-EVO or 25.4R1-S3-EVO or 26.2R1-S2-EVO or 25.2X100-D35-EVO, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Juniper Networks | Junos OS | 25.2 up to, but not including, 25.2R2-S2; 25.4 up to, but not including, 25.4R1-S3; 26.2 up to, but not including, 26.2R1-S2 | 25.2R2-S2, 25.4R1-S3, 26.2R1-S2 |
| Juniper Networks | Junos OS Evolved | 25.2 up to, but not including, 25.2R2-S2-EVO; 25.4 up to, but not including, 25.4R1-S3-EVO; 26.2 up to, but not including, 26.2R1-S2-EVO; 23.4X100; 25.2X100 up to, but not including, 25.2X100-D35-EVO; 25.4X300 up to, but not including, 25.4X300-D40-EVO | 25.2R2-S2-EVO, 25.4R1-S3-EVO, 26.2R1-S2-EVO, 25.2X100-D35-EVO, 25.4X300-D40-EVO |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (juniper.net).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (juniper.net) |
| CVSS 3.1 | 7.5 | High | CNA (juniper.net) |
Official description
A NULL Pointer Dereference vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a remote unauthenticated BGP peer to cause a denial of service via a specific BGP FlowSpec update received by an affected BGP session.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How developers prevent this class of flaw
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Select a programming language that is not susceptible to these issues.
- Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Junos OS
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 7.5 High severity
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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