Vulnerability-Lookup

SUSE-SU-2026:22284-1

Vulnerability from csaf_suse - Published: 2026-06-25 11:50 - Updated: 2026-09-16 19:59

Summary

Security update for libssh2_org

Severity

Important

Notes

Title of the patch: Security update for libssh2_org

Description of the patch: This update for libssh2_org fixes the following issues - CVE-2026-55199: pre-Authentication DoS via SSH_MSG_EXT_INFO Handler (bsc#1268530). - CVE-2026-55200: out-of-Bounds write via Unchecked packet_length in transport.c (bsc#1268531).

Patchnames: SUSE-SL-Micro-6.2-1078

CVE-2026-55199

5.9 (Medium)


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

Affected products

Recommended 4 products

Product	Version	Remediation
Unresolved product id: SUSE Linux Micro 6.2:libssh2-1-1.11.1-160000.4.1.aarch64	—	Vendor Fix
Unresolved product id: SUSE Linux Micro 6.2:libssh2-1-1.11.1-160000.4.1.ppc64le	—	Vendor Fix
Unresolved product id: SUSE Linux Micro 6.2:libssh2-1-1.11.1-160000.4.1.s390x	—	Vendor Fix
Unresolved product id: SUSE Linux Micro 6.2:libssh2-1-1.11.1-160000.4.1.x86_64	—	Vendor Fix

Threats

Impact moderate

CVE-2026-55200

8.1 (High)


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

Affected products

Recommended 4 products, the same list as for CVE-2026-55199

Threats

Impact important

References

14 references

URL	Category
https://www.suse.com/support/security/rating/	external
https://ftp.suse.com/pub/projects/security/csaf/s…	self
https://www.suse.com/support/update/announcement/…	self
https://lists.suse.com/pipermail/sle-updates/2026…	self
https://bugzilla.suse.com/1268530	self
https://bugzilla.suse.com/1268531	self
https://www.suse.com/security/cve/CVE-2026-55199/	self
https://www.suse.com/security/cve/CVE-2026-55200/	self
https://www.suse.com/security/cve/CVE-2026-55199	external
https://bugzilla.suse.com/1268530	external
https://bugzilla.suse.com/1270343	external
https://www.suse.com/security/cve/CVE-2026-55200	external
https://bugzilla.suse.com/1268531	external
https://bugzilla.suse.com/1271707	external

JSON

To clipboard

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  ]
}

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

Vulnerability from cvelistv5 – Published: 2026-06-17 18:44 – Updated: 2026-07-14 21:33 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 · CISA-ADP (v2.0.3)

Decision recorded 2026-06-18 15:31 UTC

CWE

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

Assigner

VulnCheck mitre root

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) cpe:2.3:a:libssh2:libssh2::::::::

Date Public

2026-04-15 00:00

Credits

Tristan Madani (@TristanInSec)

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-55199",
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                  },
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                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-18T15:31:38.712448Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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          "value": "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."
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CVE-2026-55200 (GCVE-0-2026-55200)

Vulnerability from cvelistv5 – Published: 2026-06-17 19:03 – Updated: 2026-07-14 21:33 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 · CISA-ADP (v2.0.3)

Decision recorded 2026-06-17 00:00 UTC

CWE

CWE-680 - Integer Overflow to Buffer Overflow

Assigner

VulnCheck mitre root

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) cpe:2.3:a:libssh2:libssh2::::::::

Date Public

2026-06-12 00:00

Credits

Tristan Madani (@TristanInSec)

Show details on NVD website

JSON

To clipboard

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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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

SUSE-SU-2026:22284-1

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

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

Tags

Sightings

Nomenclature

Related by attack behaviour