Critical severity · published Jan 30, 2026
CVE-2020-37056
Crystal Shard http-protection 0.2.0 contains an IP spoofing vulnerability that allows attackers to bypass protection middleware by manipulating request headers
9.8
CVSS
0.6%
EPSS
No
On KEV
Description
Crystal Shard http-protection 0.2.0 contains an IP spoofing vulnerability that allows attackers to bypass protection middleware by manipulating request headers. Attackers can hardcode consistent IP values across X-Forwarded-For, X-Client-IP, and X-Real-IP headers to circumvent security checks and gain unauthorized access.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-37056
CVE.org
https://www.cve.org/CVERecord?id=CVE-2020-37056
github.com
https://github.com/rogeriozambon/http-protection
www.exploit-db.com
https://www.exploit-db.com/exploits/48533
www.vulncheck.com
https://www.vulncheck.com/advisories/crystal-shard-http-protection-ip-spoofing-bypass