CVE-2026-55841

{"id": "CVE-2026-55841", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55841", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-01T02:02:52.990384Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "Graylog2", "product": "graylog2-server", "versions": [{"status": "affected", "version": "< 6.3.12"}, {"status": "affected", "version": ">= 7.0.0-alpha.1, < 7.0.7"}, {"status": "affected", "version": ">= 7.1.0-alpha.1, < 7.1.2"}]}]}], "published": "2026-08-28T23:17:07.840", "references": [{"url": "https://github.com/Graylog2/graylog2-server/commit/793df6e8202ea55c15a762e47a2a8a775961dd3f", "source": "security-advisories@github.com"}, {"url": "https://github.com/Graylog2/graylog2-server/commit/85dc699d6319aea433583dc239077a3a799c8627", "source": "security-advisories@github.com"}, {"url": "https://github.com/Graylog2/graylog2-server/commit/d5051e604c962ef3d4e5e8e434d0ff4907d2140d", "source": "security-advisories@github.com"}, {"url": "https://github.com/Graylog2/graylog2-server/commit/dde76d7432c469887d9a95c208083c5f0f73c70d", "source": "security-advisories@github.com"}, {"url": "https://github.com/Graylog2/graylog2-server/pull/26050", "source": "security-advisories@github.com"}, {"url": "https://github.com/Graylog2/graylog2-server/pull/26056", "source": "security-advisories@github.com"}, {"url": "https://github.com/Graylog2/graylog2-server/pull/26057", "source": "security-advisories@github.com"}, {"url": "https://github.com/Graylog2/graylog2-server/pull/26059", "source": "security-advisories@github.com"}, {"url": "https://github.com/Graylog2/graylog2-server/security/advisories/GHSA-gqr6-r77p-c2pj", "source": "security-advisories@github.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-138"}]}], "descriptions": [{"lang": "en", "value": "Graylog is a free and open log management platform. Prior to Graylog Server versions 6.3.12, 7.0.7, and 7.1.2 and Graylog Forwarder version 7.3, the FortiGate key-value syslog parser in graylog2-server/src/main/java/org/graylog2/inputs/codecs/GLFortiGateSyslogEvent.java and graylog2-server/src/main/java/org/graylog2/inputs/codecs/SyslogCodec.java mishandles field-like text inside quoted values. GLFortiGateSyslogEvent.getFields() uses KV_PATTERN and QUOTED_KV_PATTERN, while SyslogCodec.parse() invokes the FortiGateSyslogEvent parser; crafted values containing = or backslash-escaped quotes can cause embedded keys such as srcip, dstip, date, time, and tz to remove or overwrite original top-level fields or produce an invalid message that Graylog discards. An unauthenticated network sender who can submit syslog messages can therefore manipulate security-log fields or evade logging to obscure malicious activity. This issue is fixed in Graylog Server versions 6.3.12, 7.0.7, and 7.1.2 and Graylog Forwarder version 7.3."}], "lastModified": "2026-09-09T21:09:13.080", "sourceIdentifier": "security-advisories@github.com"}