CVE-2026-33787: An Improper Check for Unusual or Exceptional Conditions vulnerability in the chassis control daemon (chassisd)

Routine

MEDIUM 5.5MITIGATE

CVE-2026-33787 is a medium-severity flaw (CVSS 5.5) affecting junos. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An Improper Check for Unusual or Exceptional Conditions vulnerability in the chassis control daemon (chassisd) of Juniper Networks Junos OS on SRX1500, SRX4100, SRX4200 and SRX4600 allows a local attacker with low privileges to cause a complete Denial of Service (DoS). When a specific 'show chassis' CLI command is executed, chassisd crashes and restarts which causes a momentary impact to all traffic until all modules are online again. This is

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.1% (top 99%)
CISA exploited list	No
Weakness	CWE-754
Published	2026-04-09
Last modified	2026-10-26

Publisher (CNA): Juniper Networks, Inc. · Vendor: juniper

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-09 22:16 UTCPublished CVE record published
2026-10-26 22:10 UTCUpdated Record last modified

juniper junos MITIGATE

Affected: 23.2 · 23.2 r1 · 23.2 r1-s1 · 23.2 r1-s2 · 23.2 r2 · 23.2 r2-s1 · 23.2 r2-s2 · 23.2 r2-s3

Fixed in: no fixed release known

Safe to downgrade to: a release before 23.2

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33787?

junos: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-33787 being exploited?

CVE-2026-33787 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33787 affect?

CVE-2026-33787 affects junos. Severity is medium (CVSS 5.5). An Improper Check for Unusual or Exceptional Conditions vulnerability in the chassis control daemon (chassisd) of Juniper Networks Junos OS on SRX1500, SRX4100, SRX4200 and SRX4600 allows a local attacker with low privileges to cause a comp

How urgent is CVE-2026-33787?

Priority 19/100. No elevated risk signals yet.

Software pages

Juniper Junos vulnerabilities

Related CVEs

CVE-2026-33790 HIGH 7.5 UPGRADE An Improper Check for Unusual or Exceptional Conditions vulnerability in the flow daemon (flowd) of Juniper Ne
CVE-2026-33791 MEDIUM 6.7 UPGRADE UPGRADE An OS Command Injection vulnerability in the CLI processing of Juniper Networks Junos OS and Junos OS Evolved
CVE-2026-33785 HIGH 8.8 MITIGATE A Missing Authorization vulnerability in the CLI of Juniper Networks Junos OS on MX Series allows a local, aut
CVE-2026-33793 HIGH 7.8 UPGRADE UPGRADE An Execution with Unnecessary Privileges vulnerability in the User Interface (UI) of Juniper Networks Junos OS
CVE-2026-33773 MEDIUM 5.8 MITIGATE An Incorrect Initialization of Resource vulnerability in the packet forwarding engine (pfe) of Juniper Network

References

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