CVE-2026-62381

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Source
https://cve.org/CVERecord?id=CVE-2026-62381
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-62381.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-62381
Aliases
  • GHSA-jgc3-4q3p-g6xh
Published
2026-08-22T12:26:44Z
Modified
2026-10-21T02:58:54Z
Severity
  • 6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
luci-lib-px5g 2040-bit Certificate Signing Heap Buffer Overflow
Details

luci-lib-px5g (LuCI) contains a heap-based buffer overflow in the native ASN.1 encoding routine asn1_add_obj (x509write.c) when signing a certificate with a 2040-bit RSA key. For a 255-byte signature, the BIT STRING allocation is computed from the DER length encoding of 255 bytes, but the payload written after prepending the unused-bits byte is 256 bytes, requiring one additional DER length octet. As a result the allocation is 259 bytes while the tag, length, unused-bits byte, and signature require 260 bytes, and the final memcpy writes one byte beyond the heap buffer. The overflow is reachable through the exported Lua interface via create_selfsigned(); whether it is remotely exploitable depends on the embedding application. The vulnerable code is present on the openwrt-18.06 through openwrt-25.12 release branches and is absent from master, where the luci-lib-px5g package has been removed rather than patched.

Database specific 
{
    "cna_assigner":  "VulnCheck",
    "cwe_ids":  [
        "CWE-122"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/62xxx/CVE-2026-62381.json"
}
References

Affected packages

Git / github.com/openwrt/luci

Affected ranges

Type
GIT
Repo
https://github.com/openwrt/luci
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last Affected
42d72f79cd8f057f241595abc761b39dab2d9f07
Database specific
Show details 
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "last_affected":  "42d72f79cd8f057f241595abc761b39dab2d9f07"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StandardRange"
        }
    ]
}

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-62381.json"