CVE-2015-5505: The HTTP Strict Transport Security (HSTS) module 6.x-1.x before 6.x-1.1 and 7.x-1.x before 7.x-1.2 for Drupal

This month

MEDIUM 6.8DOWNGRADE

CVE-2015-5505 is a medium-severity flaw (CVSS 6.8) affecting http strict transport security. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The HTTP Strict Transport Security (HSTS) module 6.x-1.x before 6.x-1.1 and 7.x-1.x before 7.x-1.2 for Drupal does not properly implement the "include subdomains" directive, which causes the HSTS policy to not be applied to subdomains and allows man-in-the-middle attackers to have unspecified impact via unknown vectors.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.8 (Medium)
EPSS exploit chance	1.6% (top 24%)
CISA exploited list	No
Weakness	CWE-17
Published	2015-08-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: codfront labs

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2015-08-18 18:00 UTCPublished CVE record published
2026-06-17 00:29 UTCUpdated Record last modified

codfront labs http strict transport security DOWNGRADE

Affected: 6.x-1.0 · 6.x-1.0 rc1 · 6.x-1.x dev · 7.x-1.0 · 7.x-1.0 rc1 · 7.x-1.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.x-1.0

1. Check installed version

apt-cache policy http-strict-transport-security || rpm -q http-strict-transport-security || http-strict-transport-security --version

2. No fixed release: DOWNGRADE to a release before 6.x-1.0 (Debian / Ubuntu)

apt-cache madison http-strict-transport-security sudo apt install http-strict-transport-security=<VERSION_BEFORE_6.x-1.0> sudo apt-mark hold http-strict-transport-security

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list http-strict-transport-security sudo dnf downgrade http-strict-transport-security-<VERSION_BEFORE_6.x-1.0> sudo dnf versionlock add http-strict-transport-security

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-2015-5505?

http strict transport security: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2015-5505 being exploited?

CVE-2015-5505 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-2015-5505 affect?

CVE-2015-5505 affects http strict transport security. Severity is medium (CVSS 6.8). The HTTP Strict Transport Security (HSTS) module 6.x-1.x before 6.x-1.1 and 7.x-1.x before 7.x-1.2 for Drupal does not properly implement the "include subdomains" directive, which causes the HSTS policy to not be applied to subdomains and a

How urgent is CVE-2015-5505?

Priority 43/100. No elevated risk signals yet.

Software pages

Drupal vulnerabilities

References

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