Zulip is an open-source team collaboration tool with unique topic-based threading. In the event that 1: `ZulipLDAPAuthBackend` and an external authentication backend (any aside of `ZulipLDAPAuthBackend` and `EmailAuthBackend`) are the only ones enabled in `AUTHENTICATION_BACKENDS` in `/etc/zulip/settings.py` and 2: The organization permissions don't require invitations to join. An attacker can create a new account in the organization with an arbitrary email address in their control that's not in the organization's LDAP directory. The impact is limited to installations which have this specific combination of authentication backends as described above in addition to having `Invitations are required for joining this organization` organization permission disabled. This issue has been addressed in version 6.2. Users are advised to upgrade. Users unable to upgrade may enable the `Invitations are required for joining this organization` organization permission to prevent this issue.
総合評価: CVE-2023-28623 は中リスク（40.4/100）。CVSS 深刻度は中。悪用される可能性が高い（EPSS 0.53%、40 パーセンタイル） 推奨対応: 影響資産を整理し、修補計画に組み込んでください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.21% | 0.53% | +0.32% |
| 2 | 2026-05-21 | 0.14% | 0.21% | +0.06% |
| 3 | 2025-03-30 | — | 0.14% | — |
EPSS の全履歴 （全 6 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 6.5 | 3.1 | MEDIUM |
|
2.2 | 4.2 | [email protected] |
| 3.7 | 3.1 | LOW |
|
2.2 | 1.4 | [email protected] |
| URL | タグ |
|---|---|
| https://github.com/zulip/zulip/commit/3df1b4dd7c210c21deb6f829df19412b74573f8d | Patch Third Party Advisory |
| https://github.com/zulip/zulip/security/advisories/GHSA-7p62-pjwg-56rv | Third Party Advisory |