CVE-2026-55490

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Source

https://cve.org/CVERecord?id=CVE-2026-55490

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55490.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-55490

Aliases

GHSA-9558-77jp-g3fw

Published

2026-07-07T21:08:26Z

Modified

2026-10-28T11:14:54Z

Severity

6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator

Summary

OpenWrt: EAD Integer Underflow → Pre-Auth Denial of Service

Details

OpenWrt is a Linux operating system targeting embedded devices. Before v25.12.5, an integer underflow in handle_send_a() of the Emergency Access Daemon allows any unauthenticated attacker on the local network to crash the daemon by sending a single crafted UDP packet. The message length underflows before a bounds check and is then passed to memcpy as a very large size. This issue is fixed v25.12.5.

Database specific

{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-191"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55490.json"
}

References

Affected packages

Git / github.com/openwrt/openwrt

Affected ranges

Type

GIT

Repo

https://github.com/openwrt/openwrt

Events

Introduced

Fixed

f0a60eee2fe051741c643ea6118718aae1ef17fb

Fixed

63c0767f3d02f7b10b0f0b5293366bd059a08ca5

Database specific

Show details

{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "fixed":  "25.12.5"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "fixed":  "63c0767f3d02f7b10b0f0b5293366bd059a08ca5"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v25.12.5",
            "range":  [
                {
                    "fixed":  "f0a60eee2fe051741c643ea6118718aae1ef17fb"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

Other

reboot

v25.*

v25.12.0

v25.12.0-rc1

v25.12.0-rc2

v25.12.0-rc3

v25.12.0-rc4

v25.12.0-rc5

v25.12.1

v25.12.2

v25.12.3

v25.12.4

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55490.json"

vanir_signatures

[
    {
        "deprecated":  false,
        "digest":  {
            "line_hashes":  [
                "294419703187715450205335626593439281961",
                "183336370198843194977969389455018379548",
                "246828465639083322118010609854568930976",
                "84457392271222932470035232304643665303",
                "266454777908990435505859227404384476100",
                "130596044169283086513506835593771555624"
            ],
            "threshold":  0.9
        },
        "id":  "CVE-2026-55490-14a41e89",
        "signature_type":  "Line",
        "signature_version":  "v1",
        "source":  "https://github.com/openwrt/openwrt/commit/63c0767f3d02f7b10b0f0b5293366bd059a08ca5",
        "target":  {
            "file":  "package/network/services/ead/src/ead.c"
        }
    },
    {
        "deprecated":  false,
        "digest":  {
            "function_hash":  "46190189806779128788375976984613408786",
            "length":  540
        },
        "id":  "CVE-2026-55490-f59476cf",
        "signature_type":  "Function",
        "signature_version":  "v1",
        "source":  "https://github.com/openwrt/openwrt/commit/63c0767f3d02f7b10b0f0b5293366bd059a08ca5",
        "target":  {
            "file":  "package/network/services/ead/src/ead.c",
            "function":  "handle_send_a"
        }
    }
]

vanir_signatures_modified

"2026-10-28T11:14:54Z"