CVE-2026-57026Network attack vector

Service outage via malformed SIP INVITE processing

Published Jul 9, 2026 · Updated Jul 9, 2026

Improper SIP input validation in Juniper Networks Junos OS allows remote attackers to crash and restart the flowd daemon. The SIP plugin processes a syntactically malformed SIP INVITE without rejecting it, causing flowd to terminate and restart automatically. Exposure requires SIP ALG to be enabled on an MX Series device with SPC3 or an SRX Series device, and the restart causes a complete service outage until automatic recovery.

CVSS severity8.7
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper SIP input validation in Juniper Networks Junos OS allows remote attackers to crash and restart the flowd daemon. The SIP plugin processes a syntactically malformed SIP INVITE without rejecting it, causing flowd to terminate and restart automatically. Exposure requires SIP ALG to be enabled on an MX Series device with SPC3 or an SRX Series device, and the restart causes a complete service outage until automatic recovery.

The record

CVE
CVE-2026-57026
Published
Jul 9, 2026
Updated
Jul 9, 2026
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-1286, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

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

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=0 <23.2R2-S7
  2. Affected versionversion=23.4 <23.4R2-S8
  3. Affected versionversion=24.2 <24.2R2-S5
  4. Affected versionversion=24.4 <24.4R2-S4
  5. Affected versionversion=25.2 <25.2R2
  6. Affected versionversion=25.4 <25.4R1-S2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=0 <23.2R2-S7; version=23.4 <23.4R2-S8; version=24.2 <24.2R2-S5; version=24.4 <24.4R2-S4; version=25.2 <25.2R2; version=25.4 <25.4R1-S2

Published CVSS scores

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

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-1286Improper Validation of Syntactic Correctness of Input
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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