CVE-2025-63828: Host Header Injection vulnerability in Backdrop CMS 1.32.1 allows attackers to manipulate the Host header in p

Routine

MEDIUM 6.1DOWNGRADE

CVE-2025-63828 is a medium-severity flaw (CVSS 6.1) affecting backdrop cms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Host Header Injection vulnerability in Backdrop CMS 1.32.1 allows attackers to manipulate the Host header in password reset requests, leading to redirects to malicious domains and potential session hijacking via cookie injection.

Why this priority

Public exploit reference

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

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 86%)
CISA exploited list	No
Weakness	CWE-601
Published	2025-11-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: backdropcms

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

Am I affected?

Timeline

2025-11-18 18:16 UTCPublished CVE record published
2026-06-17 09:53 UTCUpdated Record last modified

backdropcms backdrop cms DOWNGRADE

Affected: 1.32.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.32.1

1. Check installed version

apt-cache policy backdrop-cms || rpm -q backdrop-cms || backdrop-cms --version

2. No fixed release: DOWNGRADE to a release before 1.32.1 (Debian / Ubuntu)

apt-cache madison backdrop-cms sudo apt install backdrop-cms=<VERSION_BEFORE_1.32.1> sudo apt-mark hold backdrop-cms

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

dnf --showduplicates list backdrop-cms sudo dnf downgrade backdrop-cms-<VERSION_BEFORE_1.32.1> sudo dnf versionlock add backdrop-cms

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-2025-63828?

backdrop cms: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-63828 being exploited?

CVE-2025-63828 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-2025-63828 affect?

CVE-2025-63828 affects backdrop cms. Severity is medium (CVSS 6.1). Host Header Injection vulnerability in Backdrop CMS 1.32.1 allows attackers to manipulate the Host header in password reset requests, leading to redirects to malicious domains and potential session hijacking via cookie injection.

How urgent is CVE-2025-63828?

Priority 30/100. Public exploit reference

Related CVEs

CVE-2025-44141 MEDIUM 6.1 DOWNGRADE A Cross-Site Scripting (XSS) vulnerability exists in the node creation form of Backdrop CMS 1.30.
CVE-2025-25063 MEDIUM 4.4 UPGRADE An XSS issue was discovered in Backdrop CMS 1.28.x before 1.28.5 and 1.29.x before 1.29.3
CVE-2025-25062 MEDIUM 4.4 UPGRADE An XSS issue was discovered in Backdrop CMS 1.28.x before 1.28.5 and 1.29.x before 1.29.3
CVE-2024-54123 MEDIUM 6.1 UPGRADE Backdrop CMS before 1.28.4 and 1.29.x before 1.29.2 allows XSS via an SVG document, if the SVG tag is allowed

References

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