JLSEC-2026-1086

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Source

https://github.com/JuliaLang/SecurityAdvisories.jl/blob/main/advisories/published/2026/JLSEC-2026-1086.md

Import Source

https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1086.json

JSON Data

https://api.osv.dev/v1/vulns/JLSEC-2026-1086

Upstream

CVE-2026-66033

EUVD-2026-48720

GHSA-2g8c-wcg8-r65c

Published

2026-07-31T18:09:08.751Z

Modified

2026-07-31T18:20:49.692565064Z

Severity

7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/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 CVSS Calculator

Summary

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow...

Details

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2_cipher_crypt() function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit the underflow in the expression computing blocksize minus aadlen minus authentication tag length to trigger an out-of-bounds read and a memcpy call with a near-SIZE_MAX length argument, causing immediate process crash before any authentication occurs.

Database specific

{
    "sources": [
        {
            "database_specific": {
                "status": "Analyzed"
            },
            "id": "CVE-2026-66033",
            "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-66033",
            "html_url": "https://nvd.nist.gov/vuln/detail/CVE-2026-66033",
            "modified": "2026-07-30T15:44:47.257Z",
            "imported": "2026-07-31T17:07:21.927Z",
            "published": "2026-07-24T17:17:35.263Z"
        },
        {
            "id": "GHSA-2g8c-wcg8-r65c",
            "url": "https://api.github.com/advisories/GHSA-2g8c-wcg8-r65c",
            "html_url": "https://github.com/advisories/GHSA-2g8c-wcg8-r65c",
            "modified": "2026-07-24T18:31:41Z",
            "imported": "2026-07-31T17:07:29.882Z",
            "published": "2026-07-24T18:31:29Z"
        },
        {
            "id": "EUVD-2026-48720",
            "url": "https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2026-48720",
            "html_url": "https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-48720",
            "modified": "2026-07-28T01:06:25Z",
            "imported": "2026-07-31T17:07:23.846Z",
            "published": "2026-07-24T16:35:28Z"
        }
    ],
    "license": "CC-BY-4.0"
}

References

Affected packages

Julia / LibSSH2_jll

Package

Name: LibSSH2_jll
Purl: pkg:julia/LibSSH2_jll?uuid=29816b5a-b9ab-546f-933c-edad1886dfa8

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1.11.104+0

Database specific

source

"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1086.json"