{"api_version":"1","generated_at":"2026-11-11T01:48:15+00:00","cve":"CVE-2026-107496","urls":{"html":"https://cve.report/CVE-2026-107496","api":"https://cve.report/api/cve/CVE-2026-107496.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-107496","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-107496"},"summary":{"title":"Infinite Loop in CMS_encrypt() With an EC Group Order of 1","description":"Issue summary: Encrypting a CMS message to an EC certificate whose group order\nis 1 may cause CMS_encrypt() or CMS_encrypt_ex() to loop indefinitely.\n\nImpact summary: An attacker able to supply the recipient certificate to an\napplication performing CMS encryption can cause that application to loop\nindefinitely, consuming CPU and resulting in Denial of Service.\n\nCWE: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')\n\nDescription: CMS_encrypt() and CMS_encrypt_ex() encrypt a message to one or\nmore recipient certificates and, for an EC recipient, generate an ephemeral\nkey in the recipient's group. If the certificate declares a group order of 1,\nrandom scalar generation can only produce zero. The key generation routine\nthen retries without limit while waiting for a nonzero private scalar, so the\ncall never returns.\n\nThe OpenSSL TLS and QUIC implementations do not use this path. An application\nis exposed only if it calls CMS_encrypt() or CMS_encrypt_ex() with a recipient\ncertificate whose EC parameters are attacker-controlled. Certificates with\nnormal EC group orders do not trigger the loop.\n\nOpenSSL 4.0 and later reject unknown explicit EC groups in default builds.\nThese versions are affected only when configured with the\nenable-ec_explicit_curves option.\n\nThe result is a hang that consumes a CPU core until the process is\ninterrupted, a Denial of Service. The severity is Low because the attacker\nmust supply the recipient certificate and the application must choose to\nencrypt to it; ordinary CMS encryption to trusted recipients is unaffected.\n\nThe fix makes EC key generation fail when the group has no valid nonzero\nprivate scalar, instead of retrying indefinitely.\n\nFIPS impact: no\nThe FIPS modules in 4.1, 4.0, 3.5 and 3.0 are not affected. The FIPS provider\ndoes not support arbitrary explicit EC domain parameters, so an order-1 group\nis rejected during key import before the vulnerable key generation path is\nreached.","state":"PUBLISHED","assigner":"openssl","published_at":"2026-11-10 19:18:02","updated_at":"2026-11-10 22:10:04"},"problem_types":["CWE-835","CWE-835 CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')"],"metrics":[],"references":[{"url":"https://github.com/openssl/openssl/commit/a0051cfe699bf5a047bc1c4faef65f80f7987366","name":"https://github.com/openssl/openssl/commit/a0051cfe699bf5a047bc1c4faef65f80f7987366","refsource":"openssl-security@openssl.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/openssl/openssl/commit/36e15b618decdff1b116eead6747718e6e729ad2","name":"https://github.com/openssl/openssl/commit/36e15b618decdff1b116eead6747718e6e729ad2","refsource":"openssl-security@openssl.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://openssl-library.org/news/secadv/20261110.txt","name":"https://openssl-library.org/news/secadv/20261110.txt","refsource":"openssl-security@openssl.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/openssl/openssl/commit/a8531368ddb1f86d2a2782a8b693926bb67b59e7","name":"https://github.com/openssl/openssl/commit/a8531368ddb1f86d2a2782a8b693926bb67b59e7","refsource":"openssl-security@openssl.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-107496","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-107496","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 4.1.0 4.1.1 semver","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 4.0.0 4.0.4 semver","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 3.5.0 3.5.10 semver","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 3.0.0 3.0.24 semver","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 1.1.1 1.1.1zk custom","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 1.0.2 1.0.2zt custom","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Yinxi Liu","lang":"en"},{"source":"CNA","value":"Jakub Zelenka","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"OpenSSL","vendor":"OpenSSL","versions":[{"lessThan":"4.1.1","status":"affected","version":"4.1.0","versionType":"semver"},{"lessThan":"4.0.4","status":"affected","version":"4.0.0","versionType":"semver"},{"lessThan":"3.5.10","status":"affected","version":"3.5.0","versionType":"semver"},{"lessThan":"3.0.24","status":"affected","version":"3.0.0","versionType":"semver"},{"lessThan":"1.1.1zk","status":"affected","version":"1.1.1","versionType":"custom"},{"lessThan":"1.0.2zt","status":"affected","version":"1.0.2","versionType":"custom"}]}],"credits":[{"lang":"en","type":"reporter","value":"Yinxi Liu"},{"lang":"en","type":"remediation developer","value":"Jakub Zelenka"}],"datePublic":"2026-11-10T11:00:00.000Z","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Issue summary: Encrypting a CMS message to an EC certificate whose group order<br>is 1 may cause CMS_encrypt() or CMS_encrypt_ex() to loop indefinitely.<br><br>Impact summary: An attacker able to supply the recipient certificate to an<br>application performing CMS encryption can cause that application to loop<br>indefinitely, consuming CPU and resulting in Denial of Service.<br><br>CWE: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')<br><br>Description: CMS_encrypt() and CMS_encrypt_ex() encrypt a message to one or<br>more recipient certificates and, for an EC recipient, generate an ephemeral<br>key in the recipient's group. If the certificate declares a group order of 1,<br>random scalar generation can only produce zero. The key generation routine<br>then retries without limit while waiting for a nonzero private scalar, so the<br>call never returns.<br><br>The OpenSSL TLS and QUIC implementations do not use this path. An application<br>is exposed only if it calls CMS_encrypt() or CMS_encrypt_ex() with a recipient<br>certificate whose EC parameters are attacker-controlled. Certificates with<br>normal EC group orders do not trigger the loop.<br><br>OpenSSL 4.0 and later reject unknown explicit EC groups in default builds.<br>These versions are affected only when configured with the<br>enable-ec_explicit_curves option.<br><br>The result is a hang that consumes a CPU core until the process is<br>interrupted, a Denial of Service. The severity is Low because the attacker<br>must supply the recipient certificate and the application must choose to<br>encrypt to it; ordinary CMS encryption to trusted recipients is unaffected.<br><br>The fix makes EC key generation fail when the group has no valid nonzero<br>private scalar, instead of retrying indefinitely.<br><br>FIPS impact: no<br>The FIPS modules in 4.1, 4.0, 3.5 and 3.0 are not affected. The FIPS provider<br>does not support arbitrary explicit EC domain parameters, so an order-1 group<br>is rejected during key import before the vulnerable key generation path is<br>reached."}],"value":"Issue summary: Encrypting a CMS message to an EC certificate whose group order\nis 1 may cause CMS_encrypt() or CMS_encrypt_ex() to loop indefinitely.\n\nImpact summary: An attacker able to supply the recipient certificate to an\napplication performing CMS encryption can cause that application to loop\nindefinitely, consuming CPU and resulting in Denial of Service.\n\nCWE: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')\n\nDescription: CMS_encrypt() and CMS_encrypt_ex() encrypt a message to one or\nmore recipient certificates and, for an EC recipient, generate an ephemeral\nkey in the recipient's group. If the certificate declares a group order of 1,\nrandom scalar generation can only produce zero. The key generation routine\nthen retries without limit while waiting for a nonzero private scalar, so the\ncall never returns.\n\nThe OpenSSL TLS and QUIC implementations do not use this path. An application\nis exposed only if it calls CMS_encrypt() or CMS_encrypt_ex() with a recipient\ncertificate whose EC parameters are attacker-controlled. Certificates with\nnormal EC group orders do not trigger the loop.\n\nOpenSSL 4.0 and later reject unknown explicit EC groups in default builds.\nThese versions are affected only when configured with the\nenable-ec_explicit_curves option.\n\nThe result is a hang that consumes a CPU core until the process is\ninterrupted, a Denial of Service. The severity is Low because the attacker\nmust supply the recipient certificate and the application must choose to\nencrypt to it; ordinary CMS encryption to trusted recipients is unaffected.\n\nThe fix makes EC key generation fail when the group has no valid nonzero\nprivate scalar, instead of retrying indefinitely.\n\nFIPS impact: no\nThe FIPS modules in 4.1, 4.0, 3.5 and 3.0 are not affected. The FIPS provider\ndoes not support arbitrary explicit EC domain parameters, so an order-1 group\nis rejected during key import before the vulnerable key generation path is\nreached."}],"metrics":[{"format":"other","other":{"content":{"text":"Low"},"type":"https://openssl-library.org/policies/general/security-policy/"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-835","description":"CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-11-10T18:14:18.207Z","orgId":"3a12439a-ef3a-4c79-92e6-6081a721f1e5","shortName":"openssl"},"references":[{"name":"OpenSSL Advisory","tags":["vendor-advisory"],"url":"https://openssl-library.org/news/secadv/20261110.txt"},{"name":"4.1.1 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/36e15b618decdff1b116eead6747718e6e729ad2"},{"name":"4.0.4 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/a8531368ddb1f86d2a2782a8b693926bb67b59e7"},{"name":"3.5.10 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/a0051cfe699bf5a047bc1c4faef65f80f7987366"}],"source":{"discovery":"UNKNOWN"},"title":"Infinite Loop in CMS_encrypt() With an EC Group Order of 1","x_generator":{"engine":"Vulnogram 0.2.0"}}},"cveMetadata":{"assignerOrgId":"3a12439a-ef3a-4c79-92e6-6081a721f1e5","assignerShortName":"openssl","cveId":"CVE-2026-107496","datePublished":"2026-11-10T18:14:18.207Z","dateReserved":"2026-10-08T08:31:36.278Z","dateUpdated":"2026-11-10T18:14:18.207Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-11-10 19:18:02","lastModifiedDate":"2026-11-10 22:10:04","problem_types":["CWE-835","CWE-835 CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')"],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"107496","Ordinal":"1","Title":"Infinite Loop in CMS_encrypt() With an EC Group Order of 1","CVE":"CVE-2026-107496","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"107496","Ordinal":"1","NoteData":"Issue summary: Encrypting a CMS message to an EC certificate whose group order\nis 1 may cause CMS_encrypt() or CMS_encrypt_ex() to loop indefinitely.\n\nImpact summary: An attacker able to supply the recipient certificate to an\napplication performing CMS encryption can cause that application to loop\nindefinitely, consuming CPU and resulting in Denial of Service.\n\nCWE: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')\n\nDescription: CMS_encrypt() and CMS_encrypt_ex() encrypt a message to one or\nmore recipient certificates and, for an EC recipient, generate an ephemeral\nkey in the recipient's group. If the certificate declares a group order of 1,\nrandom scalar generation can only produce zero. The key generation routine\nthen retries without limit while waiting for a nonzero private scalar, so the\ncall never returns.\n\nThe OpenSSL TLS and QUIC implementations do not use this path. An application\nis exposed only if it calls CMS_encrypt() or CMS_encrypt_ex() with a recipient\ncertificate whose EC parameters are attacker-controlled. Certificates with\nnormal EC group orders do not trigger the loop.\n\nOpenSSL 4.0 and later reject unknown explicit EC groups in default builds.\nThese versions are affected only when configured with the\nenable-ec_explicit_curves option.\n\nThe result is a hang that consumes a CPU core until the process is\ninterrupted, a Denial of Service. The severity is Low because the attacker\nmust supply the recipient certificate and the application must choose to\nencrypt to it; ordinary CMS encryption to trusted recipients is unaffected.\n\nThe fix makes EC key generation fail when the group has no valid nonzero\nprivate scalar, instead of retrying indefinitely.\n\nFIPS impact: no\nThe FIPS modules in 4.1, 4.0, 3.5 and 3.0 are not affected. The FIPS provider\ndoes not support arbitrary explicit EC domain parameters, so an order-1 group\nis rejected during key import before the vulnerable key generation path is\nreached.","Type":"Description","Title":"Infinite Loop in CMS_encrypt() With an EC Group Order of 1"}]}}}