{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-21906 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-21906 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-21906 is a high-severity denial of service vulnerability in Juniper Junos, published on 15 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-21906 and fix it if it is affected.\n\nWhat it is: CVE-2026-21906 is a high-severity denial of service vulnerability in Juniper Junos, published on 15 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-21906 in the wild and no public exploit code.\n\nAffected product: Juniper Junos. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-21906/ (Markdown: https://insights.sbomify.com/CVE-2026-21906/index.md)","id":"CVE-2026-21906","markdown":"https://insights.sbomify.com/CVE-2026-21906/index.md","name":"CVE-2026-21906","record":{"aliases":["GHSA-942f-w2gm-p948"],"analysis":{"component_type":"network_device","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"Juniper SRX firewall","requires_auth":"none","summary":"An unauthenticated attacker can crash the packet forwarding engine on Juniper SRX devices by sending a specific ICMP packet when GRE performance acceleration is enabled.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"juniper","cpe":[{"product":"junos","vendor":"juniper"}],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"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/AU:Y/R:A/V:C/RE:M/U:Red","version":"4.0"},"cwes":[{"id":"CWE-755","name":"Improper Handling of Exceptional Conditions"}],"description":"An Improper Handling of Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated network-based attacker sending a specific ICMP packet through a GRE tunnel to cause the PFE to crash and restart.\n\nWhen PowerMode IPsec (PMI) and GRE performance acceleration are enabled and the device receives a specific ICMP packet, a crash occurs in the SRX PFE, resulting in traffic loss. PMI is enabled by default, and GRE performance acceleration can be enabled by running the configuration command shown below. PMI is a mode of operation that provides IPsec performance improvements using Vector Packet Processing.\n\nNote that PMI with GRE performance acceleration is only supported on specific SRX platforms.\nThis issue affects Junos OS on the SRX Series:\n\n  *  all versions before 21.4R3-S12, \n  *  from 22.4 before 22.4R3-S8, \n  *  from 23.2 before 23.2R2-S5, \n  *  from 23.4 before 23.4R2-S5, \n  *  from 24.2 before 24.2R2-S3, \n  *  from 24.4 before 24.4R2-S1, \n  *  from 25.2 before 25.2R1-S1, 25.2R2.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":null,"headline":"Denial of service in Junos OS","id":"CVE-2026-21906","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"juniper:junos","products":["juniper:junos"],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"Junos Space: TLS/SSL server supports use of static key ciphers (ssl-static-key-ciphers)","id":"CVE-2026-21907"},"packages":[],"prev":{"headline":"Denial of service in Junos OS","id":"CVE-2026-21905"},"products":["Junos OS"],"published":"2026-01-15","related":[{"cvss_score":9.8,"headline":"Juniper Junos OS EX Series and SRX Series PHP External Variable Modification","id":"CVE-2023-36845","kev_date_added":"2023-11-13","published":"2023-08-17"},{"cvss_score":8.8,"headline":"Juniper Junos OS Path Traversal","id":"CVE-2020-1631","kev_date_added":"2022-03-25","published":"2020-05-04"},{"cvss_score":6.7,"headline":"Juniper Junos OS Improper Isolation or Compartmentalization","id":"CVE-2025-21590","kev_date_added":"2025-03-13","published":"2025-03-12"},{"cvss_score":5.3,"headline":"Juniper Junos OS SRX Series Missing Authentication for Critical Function","id":"CVE-2023-36851","kev_date_added":"2023-11-13","published":"2023-09-26"},{"cvss_score":5.3,"headline":"Juniper Junos OS EX Series PHP External Variable Modification","id":"CVE-2023-36844","kev_date_added":"2023-11-13","published":"2023-08-17"},{"cvss_score":5.3,"headline":"Juniper Junos OS SRX Series Missing Authentication for Critical Function","id":"CVE-2023-36846","kev_date_added":"2023-11-13","published":"2023-08-17"},{"cvss_score":5.3,"headline":"Juniper Junos OS EX Series Missing Authentication for Critical Function","id":"CVE-2023-36847","kev_date_added":"2023-11-13","published":"2023-08-17"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-01-16","vendors":["Juniper Networks"]},"summary":"An unauthenticated attacker can crash the packet forwarding engine on Juniper SRX devices by sending a specific ICMP packet when GRE performance acceleration is enabled.","url":"https://insights.sbomify.com/CVE-2026-21906/"}