Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 0.48% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-46511High confidence
HAXcms: Mass Token Exfiltration and Cross-Tenant Hijack
haxtheweb · haxcms-nodejs
Official source article: GitHub GHSA-X3X5-7H4H-GWXG ↗. Check the applicable product and release in the original source.
8.7HighCVSS 4.0
Within 7 days
Fix not verifiedHigh technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:Critical, raised one band.upgradedsince 8 Jun 2026
Compensating controls
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs haxtheweb haxcms-nodejs and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Open-source package ranges2 source-attributed ranges
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| npm@haxtheweb/haxcms-nodejs | <= 25.0.0 | 26.0.0 | GitHub advisory ↗upstream repository advisory · 9 Jun 2026 |
| npm@haxtheweb/haxcms-nodejs | SEMVER: introduced 0; fixed 26.0.0 | 26.0.0 | OSV record ↗aggregator derived · 10 Sep 2026 |
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Fix not verified01
What, why and how
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, an attack chain utilizing Stored XSS alongside dynamic token exposure in the `/system/api/connectionSettings` endpoint allows an authenticated attacker to perform a complete cross-tenant account takeover. The API dynamically leaks the active session's authentication tokens (including the `jwt`, `user_token`, `site_token`, and `appstore_token`) into a global JavaScript variable (`window.appSettings`). An attacker can exploit the XSS vulnerability to force a victim's browser to silently fetch their specific connection settings, extract the tokens, and exfiltrate them to an attacker-controlled webhook. Version 26.0.0 patches the issue.
What
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, an attack chain utilizing Stored XSS alongside dynamic token exposure in the `/system/api/connectionSettings` endpoint allows an authenticated attacker to perform a complete cross-tenant account takeover. The API dynamically leaks the active session's authentication tokens (including the `jwt`, `user_token`, `site_token`, and `appstore_token`) into a global JavaScript variable (`window.appSettings`). An attacker can exploit the XSS vulnerability to force a victim's browser to silently fetch their specific connection settings, extract the tokens, and exfiltrate them to an attacker-controlled webhook. Version 26.0.0 patches the issue.
Why
Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may bypass an access boundary or take over an account.
What
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, an attack chain utilizing Stored XSS alongside dynamic token exposure in the `/system/api/connectionSettings` endpoint allows an authenticated attacker to perform a complete cross-tenant account takeover. The API dynamically leaks the active session's authentication tokens (including the `jwt`, `user_token`, `site_token`, and `appstore_token`) into a global JavaScript variable (`window.appSettings`). An attacker can exploit the XSS vulnerability to force a victim's browser to silently fetch their specific connection settings, extract the tokens, and exfiltrate them to an attacker-controlled webhook. Version 26.0.0 patches the issue.
Why
Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may bypass an access boundary or take over an account.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.
- Likely attack path
- a network path → Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') → bypass an access boundary or take over an account
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-79 ↗
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.- Post-exploitation / living off the land
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix not verified
- Affected
- haxcms-nodejs: < 26.0.0
- haxcms-php: < 26.0.0
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 5 Jun 2026 · Last source change 8 Jun 2026, 15:55 UTC · CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-34890
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD not scheduled
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.