{"id":"CVE-2025-48995","aliases":["DEBIAN-CVE-2025-48995","EUVD-2025-16676","GHSA-gmhf-gg8w-jw42","PYSEC-2026-1922","UBUNTU-CVE-2025-48995"],"status":"published","title":"SignXML's signature verification with HMAC is vulnerable to a timing attack","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.","severity":{"version":"4.0","score":6.9,"vector":"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00239,"percentile":0.1509,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-208"],"published":"2025-06-02T16:23:27Z","modified":"2026-10-28T02:30:41Z","fixes":[{"ecosystem":"PyPI","package":"signxml","fixed_in":["4.0.4"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:13","package":"python-signxml","fixed_in":["4.0.5+dfsg-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"python-signxml","fixed_in":["4.0.5+dfsg-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"signxml","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.4"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"python-signxml","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.5+dfsg-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"python-signxml","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.5+dfsg-1"}]}]},{"source":"osv","ecosystem":"PyPI","package":"signxml","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.4"}]}],"versions":["0.0.1","0.1.0","0.1.1","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.1","0.4.2","0.4.3","0.4.4","0.4.5","0.4.6","0.5.0","0.6.0","1.0.0","1.0.1","1.0.2","2.0.0","2.1.4","2.10.0","2.10.1","2.2.0","2.2.1","2.2.2","2.2.3","2.2.4","2.2.6","2.3.0","2.4.0","2.5.2","2.6.0","2.7.0","2.7.1","2.7.2","2.7.3","2.8.0","2.8.1","2.8.2","2.9.0","3.0.0","3.0.1","3.0.2","3.1.0","3.1.1","3.2.0","3.2.1","3.2.2","4.0.0","4.0.1","4.0.2","4.0.3"]},{"source":"osv","ecosystem":"PyPI","package":"signxml","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.4"}]}],"versions":["0.0.1","0.1.0","0.1.1","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.1","0.4.2","0.4.3","0.4.4","0.4.5","0.4.6","0.5.0","0.6.0","1.0.0","1.0.1","1.0.2","2.0.0","2.1.4","2.10.0","2.10.1","2.2.0","2.2.1","2.2.2","2.2.3","2.2.4","2.2.6","2.3.0","2.4.0","2.5.2","2.6.0","2.7.0","2.7.1","2.7.2","2.7.3","2.8.0","2.8.1","2.8.2","2.9.0","3.0.0","3.0.1","3.0.2","3.1.0","3.1.1","3.2.0","3.2.1","3.2.2","4.0.0","4.0.1","4.0.2","4.0.3"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"python-signxml","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.3+dfsg-1","4.0.5+dfsg-1","4.0.5+dfsg-2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"python-signxml","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.0+dfsg-1","4.4.0+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"python-signxml","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.5+dfsg-2","4.2.0+dfsg-1"]}],"products":[{"vendor":"xml-security","product":"signxml"}],"references":[{"url":"https://github.com/XML-Security/signxml/security/advisories/GHSA-gmhf-gg8w-jw42","tags":["x_refsource_CONFIRM","advisory","web","report"]},{"url":"https://github.com/XML-Security/signxml/commit/1b501faaacf34cf978a52dbc6915ec11e27611cd","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-48995","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-gmhf-gg8w-jw42","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/48xxx/CVE-2025-48995.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2025-48995","tags":["advisory"]},{"url":"https://github.com/XML-Security/signxml","tags":["package"]},{"url":"https://pypi.org/project/signxml","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2025-48995","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-48995","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2025-48995","title":"SignXML's signature verification with HMAC is vulnerable to a timing attack","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.","status":"published","published":"2025-06-02T16:23:27.706Z","modified":"2025-06-02T16:41:13.27Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium","assessor":"cna"}],"cwes":["CWE-208"],"updated_at":"2026-11-02T14:32:41.41198Z"}],"euvd":[{"id":"EUVD-2025-16676","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.","status":"published","published":"2025-06-02T16:23:27Z","modified":"2025-06-02T16:41:13Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T20:32:32.485503Z"}],"ghsa":[{"id":"GHSA-gmhf-gg8w-jw42","title":"SignXML's signature verification with HMAC is vulnerable to a timing attack","description":"When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), prior versions of SignXML 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.","status":"published","published":"2025-06-05T00:37:19Z","modified":"2025-06-05T00:37:20Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium"}],"cwes":["CWE-208"],"updated_at":"2026-11-02T14:38:45.948817Z"}],"nvd":[{"id":"CVE-2025-48995","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.","status":"published","published":"2025-06-02T17:15:41.063Z","modified":"2026-06-17T09:30:38.297Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium","assessor":"secondary"}],"cwes":["CWE-208"],"updated_at":"2026-11-02T14:11:10.143444Z"}],"osv":[{"id":"CVE-2025-48995","title":"SignXML's signature verification with HMAC is vulnerable to a timing attack","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.","status":"published","published":"2025-06-02T16:23:27.706Z","modified":"2026-10-28T02:30:41.310553242Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium"}],"cwes":["CWE-208"],"updated_at":"2026-11-02T15:44:50.037003Z"},{"id":"DEBIAN-CVE-2025-48995","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.","status":"published","published":"2025-06-02T17:15:41.063Z","modified":"2026-09-01T20:05:53.668607605Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T15:45:47.378563Z"},{"id":"GHSA-gmhf-gg8w-jw42","title":"SignXML's signature verification with HMAC is vulnerable to a timing attack","description":"When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), prior versions of SignXML 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.","status":"published","published":"2025-06-05T00:37:19Z","modified":"2026-07-07T17:56:23.298719018Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium"}],"cwes":["CWE-208"],"updated_at":"2026-11-02T15:46:47.822182Z"},{"id":"PYSEC-2026-1922","title":"SignXML's signature verification with HMAC is vulnerable to a timing attack","description":"When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), prior versions of SignXML 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.","status":"published","published":"2026-07-07T16:02:53.797116Z","modified":"2026-07-07T17:48:12.603963915Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T15:52:55.537808Z"},{"id":"UBUNTU-CVE-2025-48995","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.","status":"published","published":"2025-06-02T17:15:00Z","modified":"2026-10-17T12:57:06.186463526Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T16:55:50.31802Z"}]}}