Vulnerability-Lookup

WID-SEC-W-2026-1996

Vulnerability from csaf_certbund - Published: 2026-06-17 22:00 - Updated: 2026-07-01 22:00

Summary

libssh2: Mehrere Schwachstellen

Severity

Hoch

Notes

Das BSI ist als Anbieter für die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch dafür verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgfältig im Einzelfall zu prüfen.

Produktbeschreibung: libssh2 ist eine C Bibliothek für das Anbieten von SSH2 Diensten auf Client- und Serverseite. Sie kann genutzt werden, um aus der Ferne Programme auszuführen, Dateien zu übertragen oder als sicherer und transparenter Tunnel für entfernte Programme genutzt werden.

Angriff: Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in libssh2 ausnutzen, um einen Denial of Service Angriff durchzuführen oder Code auszuführen.

Betroffene Betriebssysteme: - Linux - UNIX

CVE-2026-55199

Affected products

Known affected 7 products

Product	Identifier	Version
Open Source libssh2 <1.11.1 commit 7acf3df Open Source / libssh2		<1.11.1 commit 7acf3df
Open Source libssh2 <1.11.1 commit 1762685 Open Source / libssh2		<1.11.1 commit 1762685
Debian Linux Debian	`cpe:/o:debian:debian_linux:-`	—
SUSE Linux SUSE	`cpe:/o:suse:suse_linux:-`	—
Red Hat Enterprise Linux Red Hat	`cpe:/o:redhat:enterprise_linux:-`	—
Ubuntu Linux Ubuntu	`cpe:/o:canonical:ubuntu_linux:-`	—
SUSE openSUSE SUSE	`cpe:/o:suse:opensuse:-`	—

CVE-2026-55200

Affected products

Known affected 7 products

Product	Identifier	Version
Open Source libssh2 <1.11.1 commit 7acf3df Open Source / libssh2		<1.11.1 commit 7acf3df
Open Source libssh2 <1.11.1 commit 1762685 Open Source / libssh2		<1.11.1 commit 1762685
Debian Linux Debian	`cpe:/o:debian:debian_linux:-`	—
SUSE Linux SUSE	`cpe:/o:suse:suse_linux:-`	—
Red Hat Enterprise Linux Red Hat	`cpe:/o:redhat:enterprise_linux:-`	—
Ubuntu Linux Ubuntu	`cpe:/o:canonical:ubuntu_linux:-`	—
SUSE openSUSE SUSE	`cpe:/o:suse:opensuse:-`	—

References

12 references

URL	Category
https://wid.cert-bund.de/.well-known/csaf/white/2…	self
https://wid.cert-bund.de/portal/wid/securityadvis…	self
https://github.com/advisories/GHSA-3CFQ-4XX4-RMPG	external
https://github.com/advisories/GHSA-R8MH-X5QV-7GG2	external
https://security-tracker.debian.org/tracker/DSA-6365-1	external
https://access.redhat.com/errata/RHSA-2026:29950	external
https://github.com/bikini/exploitarium/tree/main/…	external
https://lists.opensuse.org/archives/list/security…	external
https://lists.suse.com/pipermail/sle-security-upd…	external
https://lists.opensuse.org/archives/list/security…	external
https://ubuntu.com/security/notices/USN-8486-1	external
https://lists.suse.com/pipermail/sle-security-upd…	external

JSON

To clipboard

{
  "document": {
    "aggregate_severity": {
      "text": "hoch"
    },
    "category": "csaf_base",
    "csaf_version": "2.0",
    "distribution": {
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "de-DE",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "Das BSI ist als Anbieter f\u00fcr die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch daf\u00fcr verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgf\u00e4ltig im Einzelfall zu pr\u00fcfen."
      },
      {
        "category": "description",
        "text": "libssh2 ist eine C Bibliothek f\u00fcr das Anbieten von SSH2 Diensten auf Client- und Serverseite. Sie kann genutzt werden, um aus der Ferne Programme auszuf\u00fchren, Dateien zu \u00fcbertragen oder als sicherer und transparenter Tunnel f\u00fcr entfernte Programme genutzt werden.",
        "title": "Produktbeschreibung"
      },
      {
        "category": "summary",
        "text": "Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in libssh2 ausnutzen, um einen Denial of Service Angriff durchzuf\u00fchren oder Code auszuf\u00fchren.",
        "title": "Angriff"
      },
      {
        "category": "general",
        "text": "- Linux\n- UNIX",
        "title": "Betroffene Betriebssysteme"
      }
    ],
    "publisher": {
      "category": "other",
      "contact_details": "csaf-provider@cert-bund.de",
      "name": "Bundesamt f\u00fcr Sicherheit in der Informationstechnik",
      "namespace": "https://www.bsi.bund.de"
    },
    "references": [
      {
        "category": "self",
        "summary": "WID-SEC-W-2026-1996 - CSAF Version",
        "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-1996.json"
      },
      {
        "category": "self",
        "summary": "WID-SEC-2026-1996 - Portal Version",
        "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-1996"
      },
      {
        "category": "external",
        "summary": "GitHub Advisory Database vom 2026-06-17",
        "url": "https://github.com/advisories/GHSA-3CFQ-4XX4-RMPG"
      },
      {
        "category": "external",
        "summary": "GitHub Advisory Database vom 2026-06-17",
        "url": "https://github.com/advisories/GHSA-R8MH-X5QV-7GG2"
      },
      {
        "category": "external",
        "summary": "Debian Security Advisory DSA-6365 vom 2026-06-25",
        "url": "https://security-tracker.debian.org/tracker/DSA-6365-1"
      },
      {
        "category": "external",
        "summary": "Red Hat Security Advisory RHSA-2026:29950 vom 2026-06-25",
        "url": "https://access.redhat.com/errata/RHSA-2026:29950"
      },
      {
        "category": "external",
        "summary": "PoC auf GitHub vom 2026-06-28",
        "url": "https://github.com/bikini/exploitarium/tree/main/libssh2-cve-2026-55200-poc"
      },
      {
        "category": "external",
        "summary": "openSUSE Security Update OPENSUSE-SU-2026:11109-1 vom 2026-06-26",
        "url": "https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/SRBHQ76PA4ZHTWY5F4ESYPYF3G2NLGWI/"
      },
      {
        "category": "external",
        "summary": "SUSE Security Update SUSE-SU-2026:22284-1 vom 2026-06-29",
        "url": "https://lists.suse.com/pipermail/sle-security-updates/2026-June/027040.html"
      },
      {
        "category": "external",
        "summary": "openSUSE Security Update OPENSUSE-SU-2026:21057-1 vom 2026-06-30",
        "url": "https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/TTGCWWMDYXOTZL4JJSCPDWCZPDAAQWYD/"
      },
      {
        "category": "external",
        "summary": "Ubuntu Security Notice USN-8486-1 vom 2026-06-30",
        "url": "https://ubuntu.com/security/notices/USN-8486-1"
      },
      {
        "category": "external",
        "summary": "SUSE Security Update SUSE-SU-2026:22364-1 vom 2026-07-01",
        "url": "https://lists.suse.com/pipermail/sle-security-updates/2026-July/027122.html"
      }
    ],
    "source_lang": "en-US",
    "title": "libssh2: Mehrere Schwachstellen",
    "tracking": {
      "current_release_date": "2026-07-01T22:00:00.000+00:00",
      "generator": {
        "date": "2026-07-02T09:05:55.957+00:00",
        "engine": {
          "name": "BSI-WID",
          "version": "1.6.0"
        }
      },
      "id": "WID-SEC-W-2026-1996",
      "initial_release_date": "2026-06-17T22:00:00.000+00:00",
      "revision_history": [
        {
          "date": "2026-06-17T22:00:00.000+00:00",
          "number": "1",
          "summary": "Initiale Fassung"
        },
        {
          "date": "2026-06-25T22:00:00.000+00:00",
          "number": "2",
          "summary": "Neue Updates von Debian und Red Hat aufgenommen"
        },
        {
          "date": "2026-06-28T22:00:00.000+00:00",
          "number": "3",
          "summary": "PoC aufgenommen"
        },
        {
          "date": "2026-06-29T22:00:00.000+00:00",
          "number": "4",
          "summary": "Neue Updates von SUSE aufgenommen"
        },
        {
          "date": "2026-06-30T22:00:00.000+00:00",
          "number": "5",
          "summary": "Neue Updates von Ubuntu aufgenommen"
        },
        {
          "date": "2026-07-01T22:00:00.000+00:00",
          "number": "6",
          "summary": "Neue Updates von SUSE aufgenommen"
        }
      ],
      "status": "final",
      "version": "6"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_name",
            "name": "Debian Linux",
            "product": {
              "name": "Debian Linux",
              "product_id": "2951",
              "product_identification_helper": {
                "cpe": "cpe:/o:debian:debian_linux:-"
              }
            }
          }
        ],
        "category": "vendor",
        "name": "Debian"
      },
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003c1.11.1 commit 1762685",
                "product": {
                  "name": "Open Source libssh2 \u003c1.11.1 commit 1762685",
                  "product_id": "T055595"
                }
              },
              {
                "category": "product_version",
                "name": "1.11.1 commit 1762685",
                "product": {
                  "name": "Open Source libssh2 1.11.1 commit 1762685",
                  "product_id": "T055595-fixed",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:libssh2:libssh2:1.11.1_commit_1762685"
                  }
                }
              },
              {
                "category": "product_version_range",
                "name": "\u003c1.11.1 commit 7acf3df",
                "product": {
                  "name": "Open Source libssh2 \u003c1.11.1 commit 7acf3df",
                  "product_id": "T055596"
                }
              },
              {
                "category": "product_version",
                "name": "1.11.1 commit 7acf3df",
                "product": {
                  "name": "Open Source libssh2 1.11.1 commit 7acf3df",
                  "product_id": "T055596-fixed",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:libssh2:libssh2:1.11.1_commit_7acf3df"
                  }
                }
              }
            ],
            "category": "product_name",
            "name": "libssh2"
          }
        ],
        "category": "vendor",
        "name": "Open Source"
      },
      {
        "branches": [
          {
            "category": "product_name",
            "name": "Red Hat Enterprise Linux",
            "product": {
              "name": "Red Hat Enterprise Linux",
              "product_id": "67646",
              "product_identification_helper": {
                "cpe": "cpe:/o:redhat:enterprise_linux:-"
              }
            }
          }
        ],
        "category": "vendor",
        "name": "Red Hat"
      },
      {
        "branches": [
          {
            "category": "product_name",
            "name": "SUSE Linux",
            "product": {
              "name": "SUSE Linux",
              "product_id": "T002207",
              "product_identification_helper": {
                "cpe": "cpe:/o:suse:suse_linux:-"
              }
            }
          },
          {
            "category": "product_name",
            "name": "SUSE openSUSE",
            "product": {
              "name": "SUSE openSUSE",
              "product_id": "T027843",
              "product_identification_helper": {
                "cpe": "cpe:/o:suse:opensuse:-"
              }
            }
          }
        ],
        "category": "vendor",
        "name": "SUSE"
      },
      {
        "branches": [
          {
            "category": "product_name",
            "name": "Ubuntu Linux",
            "product": {
              "name": "Ubuntu Linux",
              "product_id": "T000126",
              "product_identification_helper": {
                "cpe": "cpe:/o:canonical:ubuntu_linux:-"
              }
            }
          }
        ],
        "category": "vendor",
        "name": "Ubuntu"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-55199",
      "product_status": {
        "known_affected": [
          "T055596",
          "T055595",
          "2951",
          "T002207",
          "67646",
          "T000126",
          "T027843"
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      },
      "release_date": "2026-06-17T22:00:00.000+00:00",
      "title": "CVE-2026-55199"
    },
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      "cve": "CVE-2026-55200",
      "product_status": {
        "known_affected": [
          "T055596",
          "T055595",
          "2951",
          "T002207",
          "67646",
          "T000126",
          "T027843"
        ]
      },
      "release_date": "2026-06-17T22:00:00.000+00:00",
      "title": "CVE-2026-55200"
    }
  ]
}

CVE-2026-55199 (GCVE-0-2026-55199)

Vulnerability from cvelistv5 – Published: 2026-06-17 18:44 – Updated: 2026-06-18 15:31 X_Open Source

Title

libssh2 - Pre-Authentication DoS via SSH_MSG_EXT_INFO Handler

Summary

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.

Severity

8.2 (High)


                        
                          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

5.9 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Assigner

VulnCheck

References

3 references

URL	Tags
https://github.com/libssh2/libssh2/pull/1864	issue-tracking
https://github.com/libssh2/libssh2/commit/1762685…	patch
https://www.vulncheck.com/advisories/libssh2-pre-…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
libssh2	libssh2	Affected: 0 , ≤ 1.11.1 (semver) Unaffected: 17626857d20b3c9a1addfa45979dadcee1cd84a4 (git)

Date Public

2026-04-15 00:00

Credits

Tristan Madani (@TristanInSec)

Show details on NVD website

JSON

To clipboard

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    "adp": [
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        "metrics": [
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                "id": "CVE-2026-55199",
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          "tags": [
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          "name": "Patch Commit",
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    "dateReserved": "2026-06-16T15:53:37.764Z",
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CVE-2026-55200 (GCVE-0-2026-55200)

Vulnerability from cvelistv5 – Published: 2026-06-17 19:03 – Updated: 2026-07-01 03:55 X_Open Source

Title

libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c

Summary

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2_transport_read() that fails to enforce upper bounds on packet_length field. Remote attackers can send crafted SSH packets with excessively large packet_length values to corrupt heap memory and achieve remote code execution.

Severity

9.2 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

8.1 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-680 - Integer Overflow to Buffer Overflow

Assigner

VulnCheck

References

4 references

URL	Tags
https://github.com/libssh2/libssh2/pull/2052	issue-tracking
https://github.com/libssh2/libssh2/commit/97acf3d…	patch
https://www.vulncheck.com/advisories/libssh2-out-…	third-party-advisory
https://web.archive.org/web/20260623211210/https:…	exploit

Impacted products

1 product

Vendor	Product	Version
libssh2	libssh2	Affected: 0 , ≤ 1.11.1 (semver) Unaffected: 7acf3dfda80c91c3a8c9f2372546301d4a1a7a8 (git)

Date Public

2026-06-12 00:00

Credits

Tristan Madani (@TristanInSec)

Show details on NVD website

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

WID-SEC-W-2026-1996

CVE-2026-55199 (GCVE-0-2026-55199)

CVE-2026-55200 (GCVE-0-2026-55200)

Tags

Sightings

Nomenclature