CVE-2026-46395: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in haxtheweb haxcms-nodejs
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, the `hmacBase64()` function in the HAXcms Node.js backend contains two critical cryptographic implementation errors that together allow any unauthenticated attacker to extract the system’s private signing key and forge arbitrary admin-level JSON Web Tokens (JWTs) allowing them to get full admin access with a single HTTP request. First, the function passes the literal string "0" as the HMAC signing key instead of the key parameter, making every HAXcms instance compute identical HMACs for the same input. Then, after computing the HMAC, the function concatenates the real key parameter which is "this.privateKey + this.salt", the system’s master signing secret is directly onto the output. The combined buffer is base64-encoded and returned as the token. Every base64url token produced has the same structure: 32 bytes HMAC keyed with "0" and N bytes of `privateKey+salt`. An attacker base64-decodes any token, discards the first 32 bytes, and reads the private key directly. The `/system/api/connectionSettings` endpoint is unauthenticated and returns multiple tokens generated by this function. A single GET request to this endpoint exposes the private key. The PHP backend implements this function correctly with the actual key and returns only the hash. The PHP version produces 44-character tokens whereas the broken Node.js version produces 139+ character tokens. Version 26.0.0 fixes the issue.
AI Analysis
Technical Summary
The vulnerability arises from two cryptographic implementation errors in the hmacBase64() function of the HAXcms Node.js backend before version 26.0.0. First, the function incorrectly uses the literal string "0" as the HMAC signing key instead of the intended key parameter, causing all instances to produce identical HMACs for the same input. Second, after computing the HMAC, the function appends the actual private signing key concatenated with a salt directly to the output before base64 encoding. This results in tokens that embed the private key in cleartext after decoding. The unauthenticated /system/api/connectionSettings endpoint returns multiple such tokens, enabling any attacker to retrieve the private key by a single GET request. With the private key, attackers can forge arbitrary admin JWTs, gaining full admin access. The PHP backend does not have this flaw. The vulnerability is resolved in haxcms-nodejs version 26.0.0.
Potential Impact
An unauthenticated attacker can retrieve the system's private signing key by sending a single unauthenticated request to the /system/api/connectionSettings endpoint. This key exposure allows the attacker to forge arbitrary admin-level JWTs, effectively granting full administrative access to the system. The vulnerability severely compromises the confidentiality and integrity of the affected system. The CVSS 4.0 score is 9.3 (critical), reflecting the ease of exploitation and high impact.
Mitigation Recommendations
Version 26.0.0 of haxcms-nodejs fixes this vulnerability by correcting the hmacBase64() function implementation. Users should upgrade to version 26.0.0 or later to remediate this issue. No official patch or temporary fix is indicated beyond upgrading. Until upgraded, the system remains vulnerable. There is no indication that the vendor manages this as a cloud service or that the vulnerability is already mitigated.
CVE-2026-46395: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in haxtheweb haxcms-nodejs
Description
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0, the `hmacBase64()` function in the HAXcms Node.js backend contains two critical cryptographic implementation errors that together allow any unauthenticated attacker to extract the system’s private signing key and forge arbitrary admin-level JSON Web Tokens (JWTs) allowing them to get full admin access with a single HTTP request. First, the function passes the literal string "0" as the HMAC signing key instead of the key parameter, making every HAXcms instance compute identical HMACs for the same input. Then, after computing the HMAC, the function concatenates the real key parameter which is "this.privateKey + this.salt", the system’s master signing secret is directly onto the output. The combined buffer is base64-encoded and returned as the token. Every base64url token produced has the same structure: 32 bytes HMAC keyed with "0" and N bytes of `privateKey+salt`. An attacker base64-decodes any token, discards the first 32 bytes, and reads the private key directly. The `/system/api/connectionSettings` endpoint is unauthenticated and returns multiple tokens generated by this function. A single GET request to this endpoint exposes the private key. The PHP backend implements this function correctly with the actual key and returns only the hash. The PHP version produces 44-character tokens whereas the broken Node.js version produces 139+ character tokens. Version 26.0.0 fixes the issue.
CVSS v4.0
Score 9.3critical
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability arises from two cryptographic implementation errors in the hmacBase64() function of the HAXcms Node.js backend before version 26.0.0. First, the function incorrectly uses the literal string "0" as the HMAC signing key instead of the intended key parameter, causing all instances to produce identical HMACs for the same input. Second, after computing the HMAC, the function appends the actual private signing key concatenated with a salt directly to the output before base64 encoding. This results in tokens that embed the private key in cleartext after decoding. The unauthenticated /system/api/connectionSettings endpoint returns multiple such tokens, enabling any attacker to retrieve the private key by a single GET request. With the private key, attackers can forge arbitrary admin JWTs, gaining full admin access. The PHP backend does not have this flaw. The vulnerability is resolved in haxcms-nodejs version 26.0.0.
Potential Impact
An unauthenticated attacker can retrieve the system's private signing key by sending a single unauthenticated request to the /system/api/connectionSettings endpoint. This key exposure allows the attacker to forge arbitrary admin-level JWTs, effectively granting full administrative access to the system. The vulnerability severely compromises the confidentiality and integrity of the affected system. The CVSS 4.0 score is 9.3 (critical), reflecting the ease of exploitation and high impact.
Mitigation Recommendations
Version 26.0.0 of haxcms-nodejs fixes this vulnerability by correcting the hmacBase64() function implementation. Users should upgrade to version 26.0.0 or later to remediate this issue. No official patch or temporary fix is indicated beyond upgrading. Until upgraded, the system remains vulnerable. There is no indication that the vendor manages this as a cloud service or that the vulnerability is already mitigated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-13T21:04:10.931Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a231d8ae29bf47b50a98349
Added to database: 6/5/2026, 7:03:38 PM
Last enriched: 6/5/2026, 7:18:57 PM
Last updated: 6/6/2026, 4:52:13 AM
Views: 7
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