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Fencer Vulns
medium 5.3

CVE-2026-5078 json

morgan vulnerable to Log Forging via unneutralized control characters in :remote-user

published 2026-06-03 5 mo ago modified 2026-09-10 1 mo ago also GHSA-4vj7-5mj6-jm8m , EUVD-2026-34067

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits
0
none known

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.

Patch / fix

  • npm morgan 1.11.0
  • morgan morgan 1.11.0
  • node-morgan Debian 14 1.12.0+~1.9.10-1

debian advisories DEBIAN-CVE-2026-5078

  • nodejs24 hummingbird 1 24.18.0-0.3.hum1
  • nodejs24-bin hummingbird 1 24.18.0-0.3.hum1
  • nodejs24-npm hummingbird 1 11.16.0-1.24.18.0.0.3.hum1
  • nodejs24-libs hummingbird 1 24.18.0-0.3.hum1
  • nodejs24-npm-bin hummingbird 1 24.18.0-0.3.hum1
  • nodejs24-full-i18n hummingbird 1 24.18.0-0.3.hum1

red hat advisories RHSA-2026:38236

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-5078 updated cvss 5.3

morgan: morgan: Log forgery due to unneutralized control characters

  • Red Hat Confidential Compute Attestation openshift-sandboxed-containers/osc-pccs Red Hat Cryostat 4 cryostat/cryostat-openshift-console-plugin-rhel9 Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9 Red Hat Enterprise Linux 9 sgx-mpa, tdx-qgs, sgx-libs, sgx-pccs, linux-sgx, sgx-common, +2 more Red Hat Enterprise Linux 10 linux-sgx Red Hat Fuse 7 morgan
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images nodejs20, nodejs25
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Openshift Data Foundation 4 odf4/mcg-core-rhel9, rhceph-dev/odf4-mcg-core-rhel9 Red Hat Self-service automation portal 2 ansible-automation-platform/automation-portal
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images nodejs24 24.18.0-0.3.hum1, nodejs24-bin 24.18.0-0.3.hum1, nodejs24-libs 24.18.0-0.3.hum1, nodejs24-npm-bin 24.18.0-0.3.hum1, nodejs24-full-i18n 24.18.0-0.3.hum1, nodejs24-npm 11.16.0-1.24.18.0.0.3.hum1
    fixed: vendor fix RHSA-2026:38236
  • Red Hat Hardened Images nodejs22, nodejs26
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
npm morgan
>=1.2.0, <1.11.0
1.11.0

Affected products

  • morgan morgan

Classification

Weakness
  • CWE-117 Improper Output Neutralization for Logs

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.