Junos OS: SRX Series: Specifically malformed SSL packet causes FPC crash
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
An Improper Validation of Syntactic Correctness of Input vulnerability in the Web-Filtering module of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If an SRX device configured for UTM Web-Filtering receives a specifically malformed SSL packet, this will cause an FPC crash and restart. This issue affects Junos OS on SRX Series: * 23.2 versions from 23.2R2-S2 before 23.2R2-S5, * 23.4 versions from 23.4R2-S1 before 23.4R2-S5, * 24.2 versions before 24.2R2-S2, * 24.4 versions before 24.4R1-S3, 24.4R2. Earlier versions of Junos are also affected, but no fix is available.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- 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 | Junos OS | 23.2R2-S2 to before 23.2R2-S5; 23.4R2-S1 to before 23.4R2-S5; 24.2 to before 24.2R2-S2; 24.4 to before 24.4R1-S3, 24.4R2 | 23.2R2-S5, 23.4R2-S5, 24.2R2-S2, 24.4R1-S3, 24.4R2 | Patch available | CNA |
- Junos OS VendorJuniper Affected 23.2R2-S2 to before 23.2R2-S5; 23.4R2-S1 to before 23.4R2-S5; 24.2 to before 24.2R2-S2; 24.4 to before 24.4R1-S3, 24.4R2 Fixed in 23.2R2-S5, 23.4R2-S5, 24.2R2-S2, 24.4R1-S3, 24.4R2 Patch available CNA
CPE configurations NVD · 34
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:* | 23.2 r2-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r2-s3:*:*:*:*:*:* | 23.2 r2-s3 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r2-s4:*:*:*:*:*:* | 23.2 r2-s4 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:* | 23.4 r2-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:* | 23.4 r2-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s3:*:*:*:*:*:* | 23.4 r2-s3 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s4:*:*:*:*:*:* | 23.4 r2-s4 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:* | 24.2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:* | 24.2 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r1-s1:*:*:*:*:*:* | 24.2 r1-s1 | Vulnerable | Juniper |
- cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:* Versions 23.2 r2-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r2-s3:*:*:*:*:*:* Versions 23.2 r2-s3 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r2-s4:*:*:*:*:*:* Versions 23.2 r2-s4 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:* Versions 23.4 r2-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:* Versions 23.4 r2-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s3:*:*:*:*:*:* Versions 23.4 r2-s3 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s4:*:*:*:*:*:* Versions 23.4 r2-s4 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:* Versions 24.2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:* Versions 24.2 r1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r1-s1:*:*:*:*:*:* Versions 24.2 r1-s1 Vulnerable ·Juniper
Show 24 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:juniper:junos:24.2:r1-s2:*:*:*:*:*:* | 24.2 r1-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r2:*:*:*:*:*:* | 24.2 r2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r2-s1:*:*:*:*:*:* | 24.2 r2-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.4:-:*:*:*:*:*:* | 24.4 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.4:r1:*:*:*:*:*:* | 24.4 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.4:r1-s2:*:*:*:*:*:* | 24.4 r1-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.4:r2:*:*:*:*:*:* | 24.4 r2 | Vulnerable | Juniper |
| cpe:2.3:h:juniper:srx1500:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx1600:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx2300:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx300:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx320:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx340:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx345:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx380:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx4100:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx4120:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx4200:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx4300:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx4600:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx4700:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx5400:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx5600:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:srx5800:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
- cpe:2.3:o:juniper:junos:24.2:r1-s2:*:*:*:*:*:* Versions 24.2 r1-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r2:*:*:*:*:*:* Versions 24.2 r2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r2-s1:*:*:*:*:*:* Versions 24.2 r2-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.4:-:*:*:*:*:*:* Versions 24.4 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.4:r1:*:*:*:*:*:* Versions 24.4 r1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.4:r1-s2:*:*:*:*:*:* Versions 24.4 r1-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.4:r2:*:*:*:*:*:* Versions 24.4 r2 Vulnerable ·Juniper
- cpe:2.3:h:juniper:srx1500:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx1600:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx2300:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx300:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx320:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx340:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx345:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx380:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx4100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx4120:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx4200:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx4300:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx4600:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx4700:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx5400:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx5600:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:srx5800:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
Remediation
- Fix · CNA Junos OS (Juniper Networks) Fixed in 23.2R2-S5, 23.4R2-S5, 24.2R2-S2, 24.4R1-S3, 24.4R2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-21917
- 2026-10-03 Alias added: GHSA-hq5p-jr85-6779
References
More Juniper Junos 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-2015-04610 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
- TI-2023-18644 Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload and download arbitrary files KEVCVSS 3.1MEDIUM 5.3
- TI-2023-18640 Junos OS: EX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary files KEVCVSS 3.1MEDIUM 5.3
Sources
- CVE-2026-21917 · CVE Program
- CVE-2026-21917 · NVD
- FIRST EPSS
- GHSA-hq5p-jr85-6779 · GitHub Advisory Database · CC BY 4.0
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