| Summary | Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code. |
|---|---|
| Publication Date | May 13, 2026, 5:16 a.m. |
| Registration Date | May 15, 2026, 4:18 a.m. |
| Last Update | May 14, 2026, 12:52 a.m. |
| CVSS3.1 : CRITICAL | |
| スコア | 9.8 |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 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) | 高 |
| 完全性への影響(I) | 高 |
| 可用性への影響(A) | 高 |