CVE-2026-55199

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.91% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 60.1% of scored records. A rank, not a probability.

NVD base score

8.2 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Analyzed. NVD last modified this record on 2026-07-14.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-06-17 18:44Z4 MO AGO

Last updated

2026-07-14 21:33Z3 MO AGO

Reserved

2026-06-16

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

High (CVSS 8.2)

CNA CVSS 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

Weaknesses

• CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')Base
• CWE-606Unchecked Input for Loop ConditionBase

Data version

5.2

Document digest

cae3f1bd6d327e7451c939f69289b1446a0dfeec23418c9269d7f3815ffc5fc6

• github.comPull Requesthttps://github.com/libssh2/libssh2/pull/1864issue-tracking
• github.comPatch Commithttps://github.com/libssh2/libssh2/commit/17626857d20b3c9a1addfa45979dadcee1cd84a4patch
• www.vulncheck.comhttps://www.vulncheck.com/advisories/libssh2-pre-authentication-dos-via-ssh-msg-ext-info-handlerthird-party-advisory