CVE-2026-33790Network attack vector

Remote service interruption via malformed NAT64 ICMPv6

Published Apr 9, 2026 · Updated Apr 9, 2026

Denial of service in Junos OS on SRX Series allows remote attackers to restart srxpfe with a malformed ICMPv6 packet. During NAT64 translation, flowd mishandles that packet when it is destined to the device, causing the packet-forwarding process to crash. The device must use NAT64, and sustained delivery repeats the restart; IPv4 and other IPv6 traffic do not trigger the condition.

CVSS severity8.7
High
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Junos OS on SRX Series allows remote attackers to restart srxpfe with a malformed ICMPv6 packet. During NAT64 translation, flowd mishandles that packet when it is destined to the device, causing the packet-forwarding process to crash. The device must use NAT64, and sustained delivery repeats the restart; IPv4 and other IPv6 traffic do not trigger the condition.

The record

CVE
CVE-2026-33790
Published
Apr 9, 2026
Updated
Apr 9, 2026
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-754, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <21.2R3-S10
  2. Affected versionversion=21.3 <21.3*
  3. Affected versionversion=21.4 <21.4R3-S12
  4. Affected versionversion=22.1 <22.1*
  5. Affected versionversion=22.2 <22.2R3-S8
  6. Affected versionversion=22.3 <22.3*
  7. Affected versionversion=22.4 <22.4R3-S9
  8. Affected versionversion=23.2 <23.2R2-S6
  9. Affected versionversion=23.4 <23.4R2-S7
  10. Affected versionversion=24.2 <24.2R2-S3
  11. Affected versionversion=24.4 <24.4R2-S3
  12. Affected versionversion=25.2 <25.2R1-S2, 25.2R2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=0 <21.2R3-S10; version=21.3 <21.3*; version=21.4 <21.4R3-S12; version=22.1 <22.1*; version=22.2 <22.2R3-S8; version=22.3 <22.3*; version=22.4 <22.4R3-S9; version=23.2 <23.2R2-S6; version=23.4 <23.4R2-S7; version=24.2 <24.2R2-S3; version=24.4 <24.4R2-S3; version=25.2 <25.2R1-S2, 25.2R2

Published CVSS scores

7.5Juniper Networks, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7Juniper Networks, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
T1499.004Application or System Exploitation Flood

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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