NVD Vulnerability Detail
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CVE-2026-5078
Summary

Impact: The morgan logging middleware's :remote-user token extracts the Basic auth username from the Authorization request header and writes it to the log stream without neutralizing control characters. An unauthenticated attacker can send a crafted Authorization Basic header containing CR or LF bytes to inject forged log lines, breaking the one-request-per-line structure of access logs and enabling log forgery against downstream log consumers. The built-in combined, common, default, and short formats are affected, as well as any custom format that references :remote-user. Affected versions: morgan 1.2.0 through 1.10.1. Patches: upgrade to morgan 1.11.0, which neutralizes control characters in the :remote-user token output. Workarounds: use a custom format string that does not include :remote-user.

Publication Date June 3, 2026, 5:16 p.m.
Registration Date June 4, 2026, 4:16 a.m.
Last Update June 3, 2026, 5:16 p.m.
CVSS3.1 : MEDIUM
スコア 5.3
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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)
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) なし
完全性への影響(I)
可用性への影響(A) なし
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