{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-55199 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-55199 is a high-severity denial of service vulnerability in libssh2, published on 17 Jun 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-2026-55199 and fix it if it is affected.\n\nWhat it is: CVE-2026-55199 is a high-severity denial of service vulnerability in libssh2, published on 17 Jun 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-2026-55199 in the wild and no public exploit code.\n\nAffected product: libssh2. 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-2026-55199/ (Markdown: https://insights.sbomify.com/CVE-2026-55199/index.md)","id":"CVE-2026-55199","markdown":"https://insights.sbomify.com/CVE-2026-55199/index.md","name":"CVE-2026-55199","record":{"aliases":["ALPINE-CVE-2026-55199","AZL-90933","BELL-CVE-2026-55199","DEBIAN-CVE-2026-55199","ECHO-3e02-3a01-4ae3","GHSA-3cfq-4xx4-rmpg","JLSEC-2026-660","MINI-3847-fjg8-8j3g","OESA-2026-3222","ROOT-OS-DEBIAN-11-CVE-2026-55199","SUSE-SU-2026:22438-1","SUSE-SU-2026:3074-1","SUSE-SU-2026:3076-1","SUSE-SU-2026:3082-1","UBUNTU-CVE-2026-55199"],"analysis":{"component_type":"library","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"SSH client library","requires_auth":"none","summary":"A malicious SSH server can cause client CPU exhaustion via a crafted extension count in libssh2, leading to denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[{"product":"libssh2","vendor":"libssh2"}],"cvss":{"score":8.2,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-835","name":"Loop with Unreachable Exit Condition"}],"description":"libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSH_MSG_EXT_INFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can set nr_extensions to 0xFFFFFFFF during key exchange, causing the client to spin in a tight CPU loop for over 60 seconds because return values from _libssh2_get_string() are unchecked and the session timeout does not apply to CPU-bound loops.","ecosystems":["SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS","SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS","SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS","SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS","SUSE:Linux Enterprise Micro 5.3","SUSE:Linux Enterprise Micro 5.4","SUSE:Linux Enterprise Micro 5.5","SUSE:Linux Enterprise Module for Basesystem 15 SP7","SUSE:Linux Enterprise Server 15 SP4-LTSS","SUSE:Linux Enterprise Server 15 SP5-LTSS","SUSE:Linux Enterprise Server 15 SP6-LTSS","SUSE:Linux Enterprise Server for SAP Applications 15 SP4","SUSE:Linux Enterprise Server for SAP Applications 15 SP5","SUSE:Linux Enterprise Server for SAP Applications 15 SP6","SUSE:Linux Micro 6.0"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"libssh2 - Pre-Authentication DoS via SSH_MSG_EXT_INFO Handler","id":"CVE-2026-55199","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":18,"n_references":3,"next":{"headline":"libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c","id":"CVE-2026-55200"},"packages":[{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS","fixed":["1.11.0-150000.4.32.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP4-ESPOS","source":"SUSE-SU-2026:3082-1"},{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP4-ESPOS","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS","fixed":["1.11.0-150000.4.32.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP4-LTSS","source":"SUSE-SU-2026:3082-1"},{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP4-LTSS","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP5-ESPOS","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP5-LTSS","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.3","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.3","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.4","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.4","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.5","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.5","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise Module for Basesystem 15 SP7","fixed":["1.11.0-150600.20.3.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Module%20for%20Basesystem%2015%20SP7","source":"SUSE-SU-2026:3076-1"},{"ecosystem":"SUSE:Linux Enterprise Server 15 SP4-LTSS","fixed":["1.11.0-150000.4.32.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP4-LTSS","source":"SUSE-SU-2026:3082-1"},{"ecosystem":"SUSE:Linux Enterprise Server 15 SP4-LTSS","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP4-LTSS","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise Server 15 SP5-LTSS","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP5-LTSS","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise Server 15 SP6-LTSS","fixed":["1.11.0-150600.20.3.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP6-LTSS","source":"SUSE-SU-2026:3076-1"},{"ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 15 SP4","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2015%20SP4","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 15 SP5","fixed":["1.11.0-150200.9.5.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2015%20SP5","source":"SUSE-SU-2026:3074-1"},{"ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 15 SP6","fixed":["1.11.0-150600.20.3.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2015%20SP6","source":"SUSE-SU-2026:3076-1"},{"ecosystem":"SUSE:Linux Micro 6.0","fixed":["1.11.0-3.1"],"introduced":["0"],"last_affected":[],"package":"libssh2_org","purl":"pkg:rpm/suse/libssh2_org\u0026distro=SUSE%20Linux%20Micro%206.0","source":"SUSE-SU-2026:22438-1"}],"prev":{"headline":"Hermes WebUI \u003c 0.51.443 - Cross-Profile Session Data Exfiltration via Session Export Endpoint","id":"CVE-2026-55198"},"products":["libssh2"],"published":"2026-06-17","related":[{"cvss_score":9.2,"headline":"libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c","id":"CVE-2026-55200","kev_date_added":null,"published":"2026-06-17"},{"cvss_score":8.7,"headline":"libssh2 Double-Free Heap Corruption via sftp_open()","id":"CVE-2026-66032","kev_date_added":null,"published":"2026-07-24"},{"cvss_score":8.7,"headline":"libssh2 Integer Underflow DoS via AES-GCM Cipher Negotiation","id":"CVE-2026-66033","kev_date_added":null,"published":"2026-07-24"},{"cvss_score":8.3,"headline":"libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation","id":"CVE-2026-58050","kev_date_added":null,"published":"2026-06-28"},{"cvss_score":8.3,"headline":"libssh2 - Free of Uninitialized Pointer in publickey List Cleanup","id":"CVE-2026-58051","kev_date_added":null,"published":"2026-06-28"},{"cvss_score":8.3,"headline":"libssh2 - Heap Buffer Over-read via sftp_symlink() in sftp.c","id":"CVE-2025-15661","kev_date_added":null,"published":"2026-06-18"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"SUSE","prefix":"SUSE"},{"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-14","vendors":["libssh2"]},"summary":"A malicious SSH server can cause client CPU exhaustion via a crafted extension count in libssh2, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2026-55199/"}