Out-of-bounds write in Juniper Session Smart Router corrupts TCP payloads
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
An out-of-bounds write in TCP header processing in Juniper Networks Session Smart Router lets an attacker corrupt TCP payload data and possibly cause session desynchronization. The flaw is triggered by a transit TCP packet with an oversized SACK option length, and the attack works without authentication and with no user interaction, but it is hard to carry out.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
An Out-of-Bounds Write vulnerability in the TCP header processing in Juniper Networks Session Smart Router allows an attacker to corrupt TCP payload data and potentially cause session desynchronization via a transit TCP packet with an oversized SACK option length.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Juniper | Session Smart Router | before 7.0.5; 7.1.0 to before 7.1.7; 7.2.0 to before 7.2.3 | 7.0.5, 7.1.7, 7.2.3 | Patch available | CNA |
- Session Smart Router VendorJuniper Affected before 7.0.5; 7.1.0 to before 7.1.7; 7.2.0 to before 7.2.3 Fixed in 7.0.5, 7.1.7, 7.2.3 Patch available CNA
Remediation
Upgrade Juniper Networks Session Smart Router to 7.0.5, 7.1.7, or 7.2.3, which fix affected ranges before 7.0.5, from 7.1.0 before 7.1.7, and from 7.2.0 before 7.2.3.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA Session Smart Router (Juniper Networks) Fixed in 7.0.5, 7.1.7, 7.2.3
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Juniper Networks Session Smart Router — supportportal.juniper.net/JSA112183
16 records Highest priority Priority MEDIUM 5 MEDIUM, 11 LOW
Other records, highest priority first
- TI-2026-82040 Missing authentication in Juniper Session Smart Router grants admin accessPriority MEDIUM 49
- TI-2026-82044 OS command injection in Juniper Session Smart Router and ConductorPriority MEDIUM 42
- TI-2026-82034 OS command injection in Juniper Session Smart Router and ConductorPriority MEDIUM 42
Timeline
- 2026-10-28 Threatist record created from CVE-2026-103392
- 2026-10-28 Alias added: GHSA-5q73-79v3-mp67
- 2026-11-05 CISA SSVC decision points changed
References
More Juniper vulnerabilities
- TI-2023-18638 Junos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to… KEVCVSS 3.1CRITICAL 9.8
- TI-2020-01585 Out of Cycle Security Advisory: Junos OS: Security vulnerability in J-Web and web based (HTTP/HTTPS) services KEVCVSS 3.1CRITICAL 9.8
- TI-2015-06436 Juniper ScreenOS 6.2.0r15 through 6.2.0r18, 6.3.0r12 before 6.3.0r12b, 6.3.0r13 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2022-20885 Apache Commons Text prior to 1.10.0 allows RCE when applied to untrusted input due to insecure interpolation defaults CVSS 3.1CRITICAL 9.8
- TI-2015-04610 Assertion failure in ISC BIND named via TKEY queries KEVCVSS 3.1HIGH 7.5
- TI-2025-15550 Junos OS: An local attacker with shell access can execute arbitrary code KEVCVSS 4.0MEDIUM 6.7
Sources
- CVE-2026-103392 · CVE Program
- CVE-2026-103392 · NVD
- FIRST EPSS
- GHSA-5q73-79v3-mp67 · GitHub Advisory Database · CC BY 4.0
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