CVE-2026-42859

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Source
https://cve.org/CVERecord?id=CVE-2026-42859
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42859.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-42859
Aliases
  • GHSA-567c-gpv8-qh9h
Downstream
Published
2026-05-11T17:36:08.143Z
Modified
2026-08-12T16:24:23.852455Z
Severity
  • 8.1 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U CVSS Calculator
Summary
Neat VNC: Buffer overflow due to oversized RSA public keys
Details

Neat VNC is a VNC server library. Prior to 0.9.6, a pre-authentication stack buffer overflow exists in neatvnc in the RSA-AES security type handler. An unauthenticated remote attacker who can reach the VNC listening socket can send a crafted security type 5 (RSA-AES) or security type 129 (RSA-AES-256) handshake with an oversized client RSA public key, causing rsaaessend_challenge in src/auth/rsa-aes.c to overflow a 1024-byte on-stack buffer when encrypting the server challenge. This results in at least a denial of service via server crash. This vulnerability is fixed in 0.9.6.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-120"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42859.json"
}
References

Affected packages

Git / github.com/any1/neatvnc

Affected ranges

Type
GIT
Repo
https://github.com/any1/neatvnc
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
1f6cd6b75cc167fed3a19a9d1552a1f662f6b337
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.9.6"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

v0.*
v0.1.0
v0.2.0
v0.3.0
v0.3.1
v0.3.2
v0.4.0
v0.5.0
v0.5.1
v0.6.0
v0.8.0
v0.9.0
v0.9.0-rc0
v0.9.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42859.json"
vanir_signatures 
[
    {
        "target": {
            "function": "on_rsa_aes_public_key",
            "file": "src/auth/rsa-aes.c"
        },
        "deprecated": false,
        "source": "https://github.com/any1/neatvnc/commit/1f6cd6b75cc167fed3a19a9d1552a1f662f6b337",
        "id": "CVE-2026-42859-8badf251",
        "signature_version": "v1",
        "digest": {
            "length": 724.0,
            "function_hash": "22221566443134491447881802408760779538"
        },
        "signature_type": "Function"
    },
    {
        "target": {
            "function": "rsa_aes_send_challenge",
            "file": "src/auth/rsa-aes.c"
        },
        "deprecated": false,
        "source": "https://github.com/any1/neatvnc/commit/1f6cd6b75cc167fed3a19a9d1552a1f662f6b337",
        "id": "CVE-2026-42859-996ec76b",
        "signature_version": "v1",
        "digest": {
            "length": 441.0,
            "function_hash": "221587621419090949003542138390782641482"
        },
        "signature_type": "Function"
    },
    {
        "target": {
            "file": "src/auth/rsa-aes.c"
        },
        "deprecated": false,
        "source": "https://github.com/any1/neatvnc/commit/1f6cd6b75cc167fed3a19a9d1552a1f662f6b337",
        "id": "CVE-2026-42859-b7996c30",
        "signature_version": "v1",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "239833167477462087320097054358452255718",
                "177321285140820575147124416256834830533",
                "6007986327389477993100476816392266200",
                "134293002946176405258026855927400365788",
                "317282120317357486130853329309623894184",
                "145415935968179123210963415518803484470",
                "263357877467086607448878692377686757482",
                "70167750186618520029095537086431579724",
                "201038992931910347927560822641689771166",
                "236909668676271202885571250521573333375",
                "316003633770106317461265877216580626379",
                "332941537523803385594930957278154597312",
                "7506084135956688257720752474382193937",
                "55120906597597281891913167855566305431",
                "226412758820377136542262339724123636231",
                "92519627057950057525535838614847068386",
                "2130760160407261929165302326125039847"
            ]
        },
        "signature_type": "Line"
    }
]
vanir_signatures_modified 
"2026-08-12T16:24:23Z"