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Medium · 5.3 CVE-2026-15603 EUVD-2026-67720GHSA-jxfw-x594-9x9m

morgan vulnerable to Log Forging via unescaped Unicode line separators

Published Aug 28, 2026 · Updated Aug 28, 2026 · Assigned by openjs

Description

morgan is an HTTP request logger middleware for Node.js. In versions prior to 1.12.0, the internal helper that escapes log token values did not neutralize the Unicode line separator characters U+0085 (Next Line), U+2028 (Line Separator), and U+2029 (Paragraph Separator). An unauthenticated remote client can place these characters in an attacker-controlled log token, for example a Basic auth username surfaced through the remote-user token, so that Unicode-aware downstream log processing splits a single request log into multiple logical records. This is a log forging issue (CWE-117) and an incomplete-fix follow-up to CVE-2026-5078, which only addressed ASCII control characters. The issue is fixed in morgan 1.12.0, which extends the escaping set to cover these Unicode line separators. Upgrade to morgan 1.12.0 to remediate.

Affected products

VendorProductAffectedFixed
morgan morgan < 1.12.0 1.12.0

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 node-morgan 1.12.0+~1.9.10-1 —
Debian 13 node-morgan No fix yet —
Debian 12 node-morgan No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 node-morgan No fix yet —
Ubuntu 26.04 LTS node-morgan No fix yet —
Ubuntu 24.04 LTS node-morgan No fix yet —
Ubuntu 22.04 LTS node-morgan No fix yet —

Affected packages

EcosystemPackageAffectedFixedRecord
npm morgan < 1.12.0 1.12.0 GHSA-jxfw-x594-9x9m

References