CVE-2026-40194
phpseclib has a variable-time HMAC comparison in SSH2::get_binary_packet() using != instead of hash_equals()
3.7
LOW
CVSS 3.1
EPSS 0.33%
描述
phpseclib is a PHP secure communications library. Starting in 0.1.1 and prior to 3.0.51, 2.0.53, and 1.0.28, phpseclib\Net\SSH2::get_binary_packet() uses PHP's != operator to compare a received SSH packet HMAC against the locally computed HMAC. != on equal-length binary strings in PHP uses memcmp(), which short-circuits on the first differing byte. This is a real variable-time comparison (CWE-208), proven by scaling benchmarks. This vulnerability is fixed in 3.0.51, 2.0.53, and 1.0.28.
如何修補 CVE-2026-40194
要修補 CVE-2026-40194,請將受影響套件升級到下列已修補版本。
- —升級至 2.0.30-2+deb11u3 或更新版本
- —升級至 3.0.19-1+deb12u5 或更新版本
- —未列出修補版本
CVE-2026-40194 正在被利用嗎?
低 — EPSS 為 0.3%,目前沒有觀察到大規模利用活動。
受影響套件(3)
- from 0, < 2.0.30-2+deb11u3
- from 0, < 3.0.19-1+deb12u5
- from 0
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 3.1 | LOW3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |