CVE-2026-101955
Junos OS: SRX Series: Malformed DNS packet causes service disruption when UTM Anti-Spam SBL is used
Description
A Stack-based Buffer Overflow vulnerability in the UTM Anti-Spam SBL of Juniper Networks Junos OS on SRX series allows an unauthenticated remote attacker to cause arbitrary code execution or a denial of service via a injected malformed DNS packet when Anti-Spam SBL inspection is enabled.
INFO
Published Date :
Oct. 14, 2026, 5:17 p.m.
Last Modified :
Oct. 14, 2026, 5:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-101955
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 8cbe9d5a-a066-4c94-8978-4b15efeae968 | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | CRITICAL | 8cbe9d5a-a066-4c94-8978-4b15efeae968 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update Junos OS to the latest version.
- Disable Anti-Spam SBL inspection if not required.
- Review Juniper security advisories for patches.
- Monitor network traffic for malformed DNS packets.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-101955.
| URL | Resource |
|---|---|
| https://supportportal.juniper.net/JSA112186 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-101955 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-101955
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-101955 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-101955 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Oct. 14, 2026
Action Type Old Value New Value Added Description A Stack-based Buffer Overflow vulnerability in the UTM Anti-Spam SBL of Juniper Networks Junos OS on SRX series allows an unauthenticated remote attacker to cause arbitrary code execution or a denial of service via a injected malformed DNS packet when Anti-Spam SBL inspection is enabled. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/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:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-121 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/101xxx/CVE-2026-101955.json">CVE-2026-101955</a> Added Reference https://supportportal.juniper.net/JSA112186