CVE-2026-5078: Impact: The morgan logging middleware's :remote-user token extracts the Basic auth username from the Authoriza

Q: How do I fix CVE-2026-5078?

morgan: upgrade to 1.11.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-5078 being exploited?

CVE-2026-5078 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-5078 affect?

CVE-2026-5078 affects morgan. Severity is medium (CVSS 5.3). 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

Q: How urgent is CVE-2026-5078?

Priority 30/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-5078 is a medium-severity flaw (CVSS 5.3) affecting morgan. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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. T

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-117
Published	2026-06-03
Last modified	2026-07-22

Publisher (CNA): openjs · Vendor: morgan project

Last updated 2026-07-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-03 08:16 UTCPublished CVE record published
2026-07-22 19:10 UTCUpdated Record last modified

morgan project morgan UPGRADE

Affected: >= 1.2.0 and < 1.11.0

Fixed in: 1.11.0

Safe to downgrade to: a release before 1.2.0

1. Check installed version

npm ls morgan

2. UPGRADE to 1.11.0

npm install morgan@">=1.11.0"

3. If no update is available yet, DOWNGRADE to a release before 1.2.0

npm view morgan versions npm install morgan@"<1.2.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-5078?

morgan: upgrade to 1.11.0. Exact commands for each OS are on this page.

Is CVE-2026-5078 being exploited?

CVE-2026-5078 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-5078 affect?

CVE-2026-5078 affects morgan. Severity is medium (CVSS 5.3). 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

How urgent is CVE-2026-5078?

Priority 30/100. Remotely exploitable, no login, no user action

References

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