| Summary | Discuz! X5.0 releases 20260320 through 20260610 contains a CAPTCHA bypass vulnerability that allows unauthenticated remote attackers to defeat challenge controls by exploiting limited complexity and predictable character sets in generated CAPTCHA images. Attackers can train a custom optical character recognition model against collected CAPTCHA samples to reliably predict challenge text, bypassing protections on login, registration, and other functionality from automated abuse. |
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| Publication Date | June 16, 2026, 5:16 a.m. |
| Registration Date | June 17, 2026, 4:13 a.m. |
| Last Update | June 16, 2026, 9:16 p.m. |
| CVSS3.1 : MEDIUM | |
| スコア | 6.5 |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| 攻撃元区分(AV) | ネットワーク |
| 攻撃条件の複雑さ(AC) | 低 |
| 攻撃に必要な特権レベル(PR) | 不要 |
| 利用者の関与(UI) | 不要 |
| 影響の想定範囲(S) | 変更なし |
| 機密性への影響(C) | 低 |
| 完全性への影響(I) | 低 |
| 可用性への影響(A) | なし |