CVE-2026-21826: HCL Digital Experience and HCL Digital Experience Compose could be susceptible to Host header injection

Routine

MEDIUM 6.1DOWNGRADEDOWNGRADE

CVE-2026-21826 is a medium-severity flaw (CVSS 6.1) affecting digital experience compose, digital experience. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

HCL Digital Experience and HCL Digital Experience Compose could be susceptible to Host header injection. An attacker can manipulate the Host header and cause the application to behave in unexpected ways.

Why this priority

No elevated risk signals yet

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	0.1% (top 96%)
CISA exploited list	No
Weakness	CWE-601
Published	2026-06-05
Last modified	2026-07-23

Publisher (CNA): HCL Software · Vendor: hcltech

Last updated 2026-07-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-05 07:16 UTCPublished CVE record published
2026-07-23 07:10 UTCUpdated Record last modified

hcltech digital experience compose DOWNGRADE

Affected: 9.5 · 9.5 cf224 · 9.5 cf225 · 9.5 cf226 · 9.5 cf227 · 9.5 cf228 · 9.5 cf229 · 9.5 cf230

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.5

1. Check installed version

apt-cache policy digital-experience-compose || rpm -q digital-experience-compose || digital-experience-compose --version

2. No fixed release: DOWNGRADE to a release before 9.5 (Debian / Ubuntu)

apt-cache madison digital-experience-compose sudo apt install digital-experience-compose=<VERSION_BEFORE_9.5> sudo apt-mark hold digital-experience-compose

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

dnf --showduplicates list digital-experience-compose sudo dnf downgrade digital-experience-compose-<VERSION_BEFORE_9.5> sudo dnf versionlock add digital-experience-compose

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.

hcltech digital experience DOWNGRADE

Affected: 9.5 · 9.5 cf17 · 9.5 cf171 · 9.5 cf172 · 9.5 cf173 · 9.5 cf18 · 9.5 cf181 · 9.5 cf182

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.5

1. Check installed version

apt-cache policy digital-experience || rpm -q digital-experience || digital-experience --version

2. No fixed release: DOWNGRADE to a release before 9.5 (Debian / Ubuntu)

apt-cache madison digital-experience sudo apt install digital-experience=<VERSION_BEFORE_9.5> sudo apt-mark hold digital-experience

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

dnf --showduplicates list digital-experience sudo dnf downgrade digital-experience-<VERSION_BEFORE_9.5> sudo dnf versionlock add digital-experience

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-2026-21826?

digital experience compose: downgrade or apply the listed mitigation; digital experience: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-21826 being exploited?

CVE-2026-21826 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-2026-21826 affect?

CVE-2026-21826 affects digital experience compose, digital experience. Severity is medium (CVSS 6.1). HCL Digital Experience and HCL Digital Experience Compose could be susceptible to Host header injection. An attacker can manipulate the Host header and cause the application to behave in unexpected ways.

How urgent is CVE-2026-21826?

Priority 22/100. No elevated risk signals yet.

Related CVEs

CVE-2026-21837 HIGH 8.8 DOWNGRADE DOWNGRADE HCL Digital Experience is affected by an OS command injection vulnerability in the Digital Asset Management AP
CVE-2026-21825 MEDIUM 6.1 DOWNGRADE DOWNGRADE HCL Digital Experience Compose is affected by a reflected cross-site scripting (XSS) vulnerability in the sear

References

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