{"id":"CVE-2025-48994","aliases":["DEBIAN-CVE-2025-48994","EUVD-2025-16666","GHSA-6vx8-pcwv-xhf4","PYSEC-2026-1921","UBUNTU-CVE-2025-48994"],"status":"published","title":"SignXML's signature verification with HMAC is vulnerable to an algorithm confusion 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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","severity":{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00228,"percentile":0.13732,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-303"],"published":"2025-06-02T16:22:08Z","modified":"2026-10-28T02:30:36Z","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-6vx8-pcwv-xhf4","tags":["x_refsource_CONFIRM","advisory","web","report"]},{"url":"https://github.com/XML-Security/signxml/commit/e3c0c2b82a3329a65d917830657649c98b8c7600","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-48994","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-6vx8-pcwv-xhf4","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/48xxx/CVE-2025-48994.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2025-48994","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-2025-48994","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-48994","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2025-48994","title":"SignXML's signature verification with HMAC is vulnerable to an algorithm confusion 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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","status":"published","published":"2025-06-02T16:22:08.966Z","modified":"2025-06-02T16:30:51.717Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-303"],"updated_at":"2026-11-02T14:32:41.41198Z"}],"euvd":[{"id":"EUVD-2025-16666","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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","status":"published","published":"2025-06-02T16:22:08Z","modified":"2025-06-02T16:30:51Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T20:32:32.485503Z"}],"ghsa":[{"id":"GHSA-6vx8-pcwv-xhf4","title":"SignXML's signature verification with HMAC is vulnerable to an algorithm confusion 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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm.\n\nStarting with signxml 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","status":"published","published":"2025-06-05T00:38:20Z","modified":"2025-06-05T00:38:22Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-303"],"updated_at":"2026-11-02T14:38:45.948817Z"}],"nvd":[{"id":"CVE-2025-48994","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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","status":"published","published":"2025-06-02T17:15:40.853Z","modified":"2026-06-17T09:30:38.18Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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-303"],"updated_at":"2026-11-02T14:11:10.143444Z"}],"osv":[{"id":"CVE-2025-48994","title":"SignXML's signature verification with HMAC is vulnerable to an algorithm confusion 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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","status":"published","published":"2025-06-02T16:22:08.966Z","modified":"2026-10-28T02:30:36.805691917Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-303"],"updated_at":"2026-11-02T15:44:50.037003Z"},{"id":"DEBIAN-CVE-2025-48994","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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","status":"published","published":"2025-06-02T17:15:40.853Z","modified":"2026-09-01T20:05:53.671624421Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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-6vx8-pcwv-xhf4","title":"SignXML's signature verification with HMAC is vulnerable to an algorithm confusion 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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm.\n\nStarting with signxml 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","status":"published","published":"2025-06-05T00:38:20Z","modified":"2026-07-07T17:57:09.762330221Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-303"],"updated_at":"2026-11-02T15:46:40.308826Z"},{"id":"PYSEC-2026-1921","title":"SignXML's signature verification with HMAC is vulnerable to an algorithm confusion 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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm.\n\nStarting with signxml 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","status":"published","published":"2026-07-07T16:02:53.867049Z","modified":"2026-07-07T17:48:12.63428152Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T15:52:55.537808Z"},{"id":"UBUNTU-CVE-2025-48994","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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.","status":"published","published":"2025-06-02T17:15:00Z","modified":"2026-10-17T12:57:04.604098185Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T16:55:50.31802Z"}]}}