CVE-2026-73494

{"id": "CVE-2026-73494", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-73494", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-09-14T19:21:20.842876Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.4, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 2.2}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "http4s", "product": "blaze", "versions": [{"status": "affected", "version": "< 0.23.18"}, {"status": "affected", "version": ">= 1.0.0-M1, < 1.0.0-M42"}]}, {"vendor": "org.http4s", "product": "blaze-http_2.13", "versions": [{"status": "affected", "version": "< 0.23.18"}, {"status": "affected", "version": ">= 1.0.0-M1, < 1.0.0-M42"}]}, {"vendor": "org.http4s", "product": "blaze-http_3", "versions": [{"status": "affected", "version": "< 0.23.18"}, {"status": "affected", "version": ">= 1.0.0-M1, < 1.0.0-M42"}]}, {"vendor": "org.http4s", "product": "http4s-blaze-server_2.13", "versions": [{"status": "affected", "version": "< 0.23.18"}]}]}], "published": "2026-09-14T18:19:58.857", "references": [{"url": "https://github.com/http4s/blaze/commit/3f7c022e306631b006dcb43a1d7f65c0d1966f17", "source": "security-advisories@github.com"}, {"url": "https://github.com/http4s/blaze/commit/4eec2007806aa9acfefb00ebb636ddc39a147a96", "source": "security-advisories@github.com"}, {"url": "https://github.com/http4s/blaze/commit/927b67753a78c13c4445dac9307f511f5c4878c3", "source": "security-advisories@github.com"}, {"url": "https://github.com/http4s/blaze/commit/a54bc9cd31758335c7f24e29763622fd03fcf734", "source": "security-advisories@github.com"}, {"url": "https://github.com/http4s/blaze/commit/c47d9675f87603f11b32a11d503626bdf9be5c7a", "source": "security-advisories@github.com"}, {"url": "https://github.com/http4s/blaze/commit/e871ebb1d27f50c98fd56988526ce42d0fee74d6", "source": "security-advisories@github.com"}, {"url": "https://github.com/http4s/blaze/releases/tag/v0.23.18", "source": "security-advisories@github.com"}, {"url": "https://github.com/http4s/blaze/releases/tag/v1.0.0-M42", "source": "security-advisories@github.com"}, {"url": "https://github.com/http4s/blaze/security/advisories/GHSA-mhvj-jhpq-885v", "source": "security-advisories@github.com"}], "vulnStatus": "Received", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-444"}]}], "descriptions": [{"lang": "en", "value": "blaze is a Scala library for building asynchronous pipelines, with a focus on network IO. Prior to 0.23.18 and from 1.0.0-M1 until 1.0.0-M42, five HTTP/1.1 conformance laxities in the hand-written Java parser under http/src/main/java/org/http4s/blaze/http/parser/ can cause blaze to derive a different request boundary than a stricter fronting intermediary. A default BlazeServerBuilder accepts invalid or valueless header field names that violate tchar syntax, obsolete folded field lines (obs-fold), unsupported Transfer-Encoding values, duplicate Content-Length fields, and requests containing both Transfer-Encoding and Content-Length. If a lenient or legacy proxy forwards the malformed bytes but interprets them differently, the disagreement can permit front-end authorization bypass, response-queue poisoning on pooled backend connections, or cache poisoning. Exploitation requires a pair of disagreeing parsers; no non-default blaze configuration is required. The affected checks are enforced in BodyAndHeaderParser and Http1ServerParser. This issue is fixed in versions 0.23.18 and 1.0.0-M42."}], "lastModified": "2026-09-14T20:16:50.707", "sourceIdentifier": "security-advisories@github.com"}