CVE-2026-57019
Last modified
CVE-2026-57019 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. An Improper Validation of Specified Quantity in Input vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS). When a specific packet is received from device in the same broadcast domain, an affected system calculates the packet size incorrectly. This causes further packet processing to fail, which triggers an FPC major error, resulting in a FPC reset impacting traffic until the FPC has automatically recovered. Affected scenarios are: MAP-T, or non-IP traffic encapsulated in IP (e.g. EPSS estimates a 0.27% chance of exploitation in the next 30 days.
Description
An Improper Validation of Specified Quantity in Input vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS). When a specific packet is received from device in the same broadcast domain, an affected system calculates the packet size incorrectly. This causes further packet processing to fail, which triggers an FPC major error, resulting in a FPC reset impacting traffic until the FPC has automatically recovered. Affected scenarios are: MAP-T, or non-IP traffic encapsulated in IP (e.g. MPLS over GRE). When this issue happens the following logs can be observed: fpc<#> CMError: /fpc/0/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_LI_INT_REG_UNROLL_TAIL_LENGTH_OVF (0x2205eb), scope: pfe, category: functional, severity: major, module: MQSS(0), type: LI: Unroll TAIL length overflow, oc_category: default fpc<#> Performing action reset-fru for error /fpc/0/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_LI_INT_REG_UNROLL_TAIL_LENGTH_OVF (0x2205eb) in module: MQSS(0) with scope: pfe category: functional level: major, oc_category: default This issue affects Junos OS on MX Series: * all versions before 23.2R2-S6, * 23.4 versions before 23.4R2-S7, * 24.2 versions before 24.2R2-S4, * 24.4 versions before 24.4R2-S4, * 25.2 versions before 25.2R2.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Juniper | Junos | < 23.2 |
| Juniper | Junos | 23.2 |
| Juniper | Junos | 23.4 |
| Juniper | Junos | 24.2 |
| Juniper | Junos | 24.4 |
| Juniper | Junos | 25.2 |
References
- https://supportportal.juniper.net/JSA110079Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-57019?
How severe is CVE-2026-57019?
How do I fix CVE-2026-57019?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-56992In multiple files, there is a possible permission bypass due…6.7
- CVE-2026-56997In Av1DecodeFrameTag of vp9hwd_headers.cc, there is a possib…8.8
- CVE-2026-57006In acfw_ffa.c, there is a possible secret read due to a logi…4.4
- CVE-2026-57008In Modem, there is a possible information disclosure due to …7.5
- CVE-2026-57012In the Setup Wizard, there is a possible remote package inst…8.4
- CVE-2026-57014In phNxpNciHal_ext_process_nfc_init_rsp of phNxpNciHal_ext.c…7.8
- CVE-2026-57020An Improper Check for Unusual or Exceptional Conditions vuln…7.1
- CVE-2026-57021An Out-of-bounds Write vulnerability in the http-gatekeeper …6.9
- CVE-2026-57022An Improper Check for Unusual or Exceptional Conditions vuln…8.2
- CVE-2026-57023An Improper Validation of Specified Quantity in Input vulner…8.7
- CVE-2026-57024A Use of Multiple Resources with Duplicate Identifier vulner…6.9
- CVE-2026-57025A Return of Pointer Value Outside of Expected Range vulnerab…6.8
Are you affected by CVE-2026-57019?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST
