CVE-2025-48995
MEDIUM EPSS 9.9%
Published Jun 2, 20251y ago · Modified Jun 17, 20262w ago
6.9 CVSS 4.0
Published Jun 2, 2025 1y ago
Last Modified Jun 17, 2026 2w ago
Description
SignXML is an implementation of the W3C XML Signature standard in Python. When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), versions of SignXML prior to 4.0.4 are vulnerable to a potential timing attack. The verifier may leak information about the correct HMAC when comparing it with the user supplied hash, allowing users to reconstruct the correct HMAC for any data.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
9.9% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-208
References 2
- github.com https://github.com/XML-Security/signxml/commit/1b501faaacf34cf978a52dbc6915ec11e27611cd
- github.com https://github.com/XML-Security/signxml/security/advisories/GHSA-gmhf-gg8w-jw42
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.