{ "document": { "aggregate_severity": { "text": "Important" }, "category": "csaf_security_advisory", "csaf_version": "2.0", "distribution": { "text": "TuxCare License Agreement", "tlp": { "label": "WHITE", "url": "https://www.first.org/tlp/" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.", "title": "Terms of Use" }, { "category": "details", "text": "* SECURITY UPDATE: out-of-bounds read from manipulated SFTP extension index\n - debian/patches/CVE-2026-3731.patch: Fix out-of-bound read in sftp\n extensions by replacing '>' with '>=' in index checks; cause: off-by-one\n error in index comparison allowing idx equal count.\n - CVE-2026-3731", "title": "Details" } ], "publisher": { "category": "vendor", "contact_details": "https://tuxcare.com/contact/", "name": "TuxCare", "namespace": "https://tuxcare.com/" }, "references": [ { "category": "self", "summary": "https://cve.tuxcare.com/els/releases/CLSA-2026:1773930007", "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1773930007" }, { "category": "self", "summary": "Canonical URL", "url": "https://security.tuxcare.com/csaf/v2/els_os/ubuntu18.04els/advisories/2026/clsa-2026_1773930007.json" } ], "tracking": { "current_release_date": "2026-03-19T14:20:54Z", "generator": { "date": "2026-03-19T14:20:54Z", "engine": { "name": "pyCSAF" } }, "id": "CLSA-2026:1773930007", "initial_release_date": "2026-03-19T14:20:54Z", "revision_history": [ { "date": "2026-03-19T14:20:54Z", "number": "1", "summary": "Initial version" } ], "status": "final", "version": "1" }, "title": "Fix CVE(s): CVE-2026-3731" }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_name", "name": "Ubuntu 18.04", "product": { "name": "Ubuntu 18.04", "product_id": "Ubuntu-18", "product_identification_helper": { "cpe": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*" } } } ], "category": "product_family", "name": "Ubuntu" } ], "category": "vendor", "name": "Canonical Ltd." }, { "branches": [ { "branches": [ { "category": "product_version", "name": "libssh-gcrypt-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product": { "name": "libssh-gcrypt-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product_id": "libssh-gcrypt-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product_identification_helper": { "purl": "pkg:deb/cloudlinux/libssh-gcrypt-dev@0.8.0~20170825.94fa1e38-1ubuntu0.7%2Btuxcare.els3?arch=amd64" } } }, { "category": "product_version", "name": "libssh-gcrypt-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product": { "name": "libssh-gcrypt-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product_id": "libssh-gcrypt-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product_identification_helper": { "purl": "pkg:deb/cloudlinux/libssh-gcrypt-4@0.8.0~20170825.94fa1e38-1ubuntu0.7%2Btuxcare.els3?arch=amd64" } } }, { "category": "product_version", "name": "libssh-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product": { "name": "libssh-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product_id": "libssh-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product_identification_helper": { "purl": "pkg:deb/cloudlinux/libssh-dev@0.8.0~20170825.94fa1e38-1ubuntu0.7%2Btuxcare.els3?arch=amd64" } } }, { "category": "product_version", "name": "libssh-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product": { "name": "libssh-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product_id": "libssh-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "product_identification_helper": { "purl": "pkg:deb/cloudlinux/libssh-4@0.8.0~20170825.94fa1e38-1ubuntu0.7%2Btuxcare.els3?arch=amd64" } } } ], "category": "architecture", "name": "amd64" }, { "branches": [ { "category": "product_version", "name": "libssh-doc-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.all", "product": { "name": "libssh-doc-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.all", "product_id": "libssh-doc-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.all", "product_identification_helper": { "purl": "pkg:deb/cloudlinux/libssh-doc@0.8.0~20170825.94fa1e38-1ubuntu0.7%2Btuxcare.els3?arch=all" } } } ], "category": "architecture", "name": "all" } ], "category": "vendor", "name": "CloudLinux" } ], "relationships": [ { "category": "default_component_of", "full_product_name": { "name": "libssh-gcrypt-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64 as a component of Ubuntu 18.04", "product_id": "Ubuntu-18:libssh-gcrypt-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64" }, "product_reference": "libssh-gcrypt-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "relates_to_product_reference": "Ubuntu-18" }, { "category": "default_component_of", "full_product_name": { "name": "libssh-gcrypt-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64 as a component of Ubuntu 18.04", "product_id": "Ubuntu-18:libssh-gcrypt-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64" }, "product_reference": "libssh-gcrypt-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "relates_to_product_reference": "Ubuntu-18" }, { "category": "default_component_of", "full_product_name": { "name": "libssh-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64 as a component of Ubuntu 18.04", "product_id": "Ubuntu-18:libssh-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64" }, "product_reference": "libssh-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "relates_to_product_reference": "Ubuntu-18" }, { "category": "default_component_of", "full_product_name": { "name": "libssh-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64 as a component of Ubuntu 18.04", "product_id": "Ubuntu-18:libssh-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64" }, "product_reference": "libssh-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "relates_to_product_reference": "Ubuntu-18" }, { "category": "default_component_of", "full_product_name": { "name": "libssh-doc-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.all as a component of Ubuntu 18.04", "product_id": "Ubuntu-18:libssh-doc-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.all" }, "product_reference": "libssh-doc-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.all", "relates_to_product_reference": "Ubuntu-18" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-3731", "cwe": { "id": "CWE-119", "name": "Improper Restriction of Operations within the Bounds of a Memory Buffer" }, "notes": [ { "category": "description", "text": "A weakness has been identified in libssh up to 0.11.3. The impacted element is the function sftp_extensions_get_name/sftp_extensions_get_data of the file src/sftp.c of the component SFTP Extension Name Handler. Executing a manipulation of the argument idx can lead to out-of-bounds read. The attack may be performed from remote. Upgrading to version 0.11.4 and 0.12.0 is sufficient to resolve this issue. This patch is called 855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60. You should upgrade the affected component.", "title": "Vulnerability description" }, { "category": "general", "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.", "title": "CVSS score applicability" } ], "product_status": { "fixed": [ "Ubuntu-18:libssh-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "Ubuntu-18:libssh-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "Ubuntu-18:libssh-doc-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.all", "Ubuntu-18:libssh-gcrypt-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "Ubuntu-18:libssh-gcrypt-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64" ] }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://cve.tuxcare.com/els/cve/CVE-2026-3731" }, { "category": "external", "summary": "https://gitlab.com/libssh/libssh-mirror/-/commit/855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60", "url": "https://gitlab.com/libssh/libssh-mirror/-/commit/855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60" }, { "category": "external", "summary": "https://vuldb.com/?ctiid.349709", "url": "https://vuldb.com/?ctiid.349709" }, { "category": "external", "summary": "https://vuldb.com/?id.349709", "url": "https://vuldb.com/?id.349709" }, { "category": "external", "summary": "https://vuldb.com/?submit.767120", "url": "https://vuldb.com/?submit.767120" }, { "category": "external", "summary": "https://www.libssh.org/files/0.12/libssh-0.12.0.tar.xz", "url": "https://www.libssh.org/files/0.12/libssh-0.12.0.tar.xz" }, { "category": "external", "summary": "https://www.libssh.org/security/advisories/libssh-2026-sftp-extensions.txt", "url": "https://www.libssh.org/security/advisories/libssh-2026-sftp-extensions.txt" } ], "release_date": "2026-03-08T11:15:00Z", "remediations": [ { "category": "vendor_fix", "date": "2026-03-19T14:20:17.153954Z", "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1773930007", "product_ids": [ "Ubuntu-18:libssh-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "Ubuntu-18:libssh-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "Ubuntu-18:libssh-doc-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.all", "Ubuntu-18:libssh-gcrypt-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "Ubuntu-18:libssh-gcrypt-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64" ], "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1773930007" } ], "scores": [ { "cvss_v3": { "attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "products": [ "Ubuntu-18:libssh-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "Ubuntu-18:libssh-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "Ubuntu-18:libssh-doc-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.all", "Ubuntu-18:libssh-gcrypt-4-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64", "Ubuntu-18:libssh-gcrypt-dev-0:0.8.0~20170825.94fa1e38-1ubuntu0.7+tuxcare.els3.amd64" ] } ], "threats": [ { "category": "impact", "details": "Important" } ] } ] }