{"api_version":"1","generated_at":"2026-09-11T14:47:17+00:00","cve":"CVE-2026-15603","urls":{"html":"https://cve.report/CVE-2026-15603","api":"https://cve.report/api/cve/CVE-2026-15603.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-15603","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-15603"},"summary":{"title":"morgan vulnerable to Log Forging via unescaped Unicode line separators","description":"morgan is an HTTP request logger middleware for Node.js. In versions prior to 1.12.0, the internal helper that escapes log token values did not neutralize the Unicode line separator characters U+0085 (Next Line), U+2028 (Line Separator), and U+2029 (Paragraph Separator). An unauthenticated remote client can place these characters in an attacker-controlled log token, for example a Basic auth username surfaced through the remote-user token, so that Unicode-aware downstream log processing splits a single request log into multiple logical records. This is a log forging issue (CWE-117) and an incomplete-fix follow-up to CVE-2026-5078, which only addressed ASCII control characters. The issue is fixed in morgan 1.12.0, which extends the escaping set to cover these Unicode line separators. Upgrade to morgan 1.12.0 to remediate.","state":"PUBLISHED","assigner":"openjs","published_at":"2026-08-28 16:17:07","updated_at":"2026-08-31 17:11:12"},"problem_types":["CWE-117","CWE-117 CWE-117: Improper Output Neutralization for Logs"],"metrics":[{"version":"3.1","source":"ce714d77-add3-4f53-aff5-83d477b104bb","type":"Secondary","score":"5.3","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"5.3","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","data":{"baseScore":5.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"}}],"references":[{"url":"https://cna.openjsf.org/security-advisories.html","name":"https://cna.openjsf.org/security-advisories.html","refsource":"ce714d77-add3-4f53-aff5-83d477b104bb","tags":["Third Party Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/expressjs/morgan/security/advisories/GHSA-jxfw-x594-9x9m","name":"https://github.com/expressjs/morgan/security/advisories/GHSA-jxfw-x594-9x9m","refsource":"ce714d77-add3-4f53-aff5-83d477b104bb","tags":["Vendor Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-15603","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-15603","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"morgan","product":"morgan","version":"affected 1.12.0 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"mfazrinizar","lang":"en"},{"source":"CNA","value":"UlisesGascon","lang":"en"},{"source":"CNA","value":"jonchurch","lang":"en"},{"source":"CNA","value":"bjohansebas","lang":"en"},{"source":"CNA","value":"iaohkut-from-NightWolf-Team","lang":"en"}],"nvd_cpes":[{"cve_year":"2026","cve_id":"15603","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"morgan_project","cpe5":"morgan","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"node.js","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"15603","cve":"CVE-2026-15603","epss":"0.002350000","percentile":"0.142880000","score_date":"2026-09-01","updated_at":"2026-09-02 00:10:39"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-15603","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-08-28T18:23:50.016435Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-08-28T18:23:58.959Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"defaultStatus":"unaffected","packageURL":"pkg:npm/morgan","product":"morgan","vendor":"morgan","versions":[{"lessThan":"1.12.0","status":"affected","version":"0","versionType":"semver"}]}],"credits":[{"lang":"en","type":"reporter","value":"mfazrinizar"},{"lang":"en","type":"remediation reviewer","value":"UlisesGascon"},{"lang":"en","type":"remediation reviewer","value":"jonchurch"},{"lang":"en","type":"remediation developer","value":"bjohansebas"},{"lang":"en","type":"reporter","value":"iaohkut-from-NightWolf-Team"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"morgan is an HTTP request logger middleware for Node.js. In versions prior to 1.12.0, the internal helper that escapes log token values did not neutralize the Unicode line separator characters U+0085 (Next Line), U+2028 (Line Separator), and U+2029 (Paragraph Separator). An unauthenticated remote client can place these characters in an attacker-controlled log token, for example a Basic auth username surfaced through the remote-user token, so that Unicode-aware downstream log processing splits a single request log into multiple logical records. This is a log forging issue (CWE-117) and an incomplete-fix follow-up to CVE-2026-5078, which only addressed ASCII control characters. The issue is fixed in morgan 1.12.0, which extends the escaping set to cover these Unicode line separators. Upgrade to morgan 1.12.0 to remediate."}],"value":"morgan is an HTTP request logger middleware for Node.js. In versions prior to 1.12.0, the internal helper that escapes log token values did not neutralize the Unicode line separator characters U+0085 (Next Line), U+2028 (Line Separator), and U+2029 (Paragraph Separator). An unauthenticated remote client can place these characters in an attacker-controlled log token, for example a Basic auth username surfaced through the remote-user token, so that Unicode-aware downstream log processing splits a single request log into multiple logical records. This is a log forging issue (CWE-117) and an incomplete-fix follow-up to CVE-2026-5078, which only addressed ASCII control characters. The issue is fixed in morgan 1.12.0, which extends the escaping set to cover these Unicode line separators. Upgrade to morgan 1.12.0 to remediate."}],"metrics":[{"cvssV3_1":{"baseScore":5.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-117","description":"CWE-117: Improper Output Neutralization for Logs","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-28T13:41:49.521Z","orgId":"ce714d77-add3-4f53-aff5-83d477b104bb","shortName":"openjs"},"references":[{"url":"https://github.com/expressjs/morgan/security/advisories/GHSA-jxfw-x594-9x9m"},{"url":"https://cna.openjsf.org/security-advisories.html"}],"title":"morgan vulnerable to Log Forging via unescaped Unicode line separators","x_generator":{"engine":"cve-kit 1.0.0"}}},"cveMetadata":{"assignerOrgId":"ce714d77-add3-4f53-aff5-83d477b104bb","assignerShortName":"openjs","cveId":"CVE-2026-15603","datePublished":"2026-08-28T13:41:49.521Z","dateReserved":"2026-07-13T15:00:54.278Z","dateUpdated":"2026-08-28T18:23:58.959Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-28 16:17:07","lastModifiedDate":"2026-08-31 17:11:12","problem_types":["CWE-117","CWE-117 CWE-117: Improper Output Neutralization for Logs"],"metrics":{"cvssMetricV31":[{"source":"ce714d77-add3-4f53-aff5-83d477b104bb","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":1.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-28T18:23:50.016435Z","id":"CVE-2026-15603","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:morgan_project:morgan:*:*:*:*:*:node.js:*:*","versionEndExcluding":"1.12.0","matchCriteriaId":"CDC81AA1-2A8D-4244-88CE-BEDC4240E5A0"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"15603","Ordinal":"1","Title":"morgan vulnerable to Log Forging via unescaped Unicode line sepa","CVE":"CVE-2026-15603","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"15603","Ordinal":"1","NoteData":"morgan is an HTTP request logger middleware for Node.js. In versions prior to 1.12.0, the internal helper that escapes log token values did not neutralize the Unicode line separator characters U+0085 (Next Line), U+2028 (Line Separator), and U+2029 (Paragraph Separator). An unauthenticated remote client can place these characters in an attacker-controlled log token, for example a Basic auth username surfaced through the remote-user token, so that Unicode-aware downstream log processing splits a single request log into multiple logical records. This is a log forging issue (CWE-117) and an incomplete-fix follow-up to CVE-2026-5078, which only addressed ASCII control characters. The issue is fixed in morgan 1.12.0, which extends the escaping set to cover these Unicode line separators. Upgrade to morgan 1.12.0 to remediate.","Type":"Description","Title":"morgan vulnerable to Log Forging via unescaped Unicode line sepa"}]}}}