CVE-2026-62381 (GCVE-0-2026-62381)
Vulnerability from cvelistv5
Published
2026-08-22 12:26
Modified
2026-08-24 19:50
Severity ?
6.9 (Medium) - 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
6.6 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
6.6 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
VLAI Severity ?
EPSS score ?
CWE
- CWE-122 - Heap-based Buffer Overflow
Summary
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.
References
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|---|---|---|
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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