{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-28435", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-02-27T15:54:05.139Z", "datePublished": "2026-03-04T19:36:33.418Z", "dateUpdated": "2026-03-04T20:39:46.131Z"}, "containers": {"cna": {"title": "Payload size limit bypass via gzip decompression in ContentReader (streaming) allows oversized request bodies in cpp-httplib", "problemTypes": [{"descriptions": [{"cweId": "CWE-400", "lang": "en", "description": "CWE-400: Uncontrolled Resource Consumption", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-409", "lang": "en", "description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xvfx-w463-6fpp", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xvfx-w463-6fpp"}, {"name": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8", "tags": ["x_refsource_MISC"], "url": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8"}], "affected": [{"vendor": "yhirose", "product": "cpp-httplib", "versions": [{"version": "< 0.35.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-04T19:36:33.418Z"}, "descriptions": [{"lang": "en", "value": "cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.35.0, cpp-httplib (httplib.h) does not enforce Server::set_payload_max_length() on the decompressed request body when using HandlerWithContentReader (streaming ContentReader) with Content-Encoding: gzip (or other supported encodings). A small compressed payload can expand beyond the configured payload limit and be processed by the application, enabling a payload size limit bypass and potential denial of service (CPU/memory exhaustion). This vulnerability is fixed in 0.35.0."}], "source": {"advisory": "GHSA-xvfx-w463-6fpp", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-03-04T20:37:10.788317Z", "id": "CVE-2026-28435", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-04T20:39:46.131Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-28435", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-04T20:37:10.788317Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-04T20:38:32.641Z"}}], "cna": {"title": "Payload size limit bypass via gzip decompression in ContentReader (streaming) allows oversized request bodies in cpp-httplib", "source": {"advisory": "GHSA-xvfx-w463-6fpp", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"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:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}}], "affected": [{"vendor": "yhirose", "product": "cpp-httplib", "versions": [{"status": "affected", "version": "< 0.35.0"}]}], "references": [{"url": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xvfx-w463-6fpp", "name": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xvfx-w463-6fpp", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8", "name": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.35.0, cpp-httplib (httplib.h) does not enforce Server::set_payload_max_length() on the decompressed request body when using HandlerWithContentReader (streaming ContentReader) with Content-Encoding: gzip (or other supported encodings). A small compressed payload can expand beyond the configured payload limit and be processed by the application, enabling a payload size limit bypass and potential denial of service (CPU/memory exhaustion). This vulnerability is fixed in 0.35.0."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-400", "description": "CWE-400: Uncontrolled Resource Consumption"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-409", "description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-04T19:36:33.418Z"}}}, "cveMetadata": {"cveId": "CVE-2026-28435", "state": "PUBLISHED", "dateUpdated": "2026-03-04T20:39:46.131Z", "dateReserved": "2026-02-27T15:54:05.139Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-03-04T19:36:33.418Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:yhirose:cpp-httplib:*:*:*:*:*:*:*:*", "matchCriteriaId": "27E6A328-789B-48B3-B888-23C091A0766D", "versionEndExcluding": "0.35.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.35.0, cpp-httplib (httplib.h) does not enforce Server::set_payload_max_length() on the decompressed request body when using HandlerWithContentReader (streaming ContentReader) with Content-Encoding: gzip (or other supported encodings). A small compressed payload can expand beyond the configured payload limit and be processed by the application, enabling a payload size limit bypass and potential denial of service (CPU/memory exhaustion). This vulnerability is fixed in 0.35.0."}], "id": "CVE-2026-28435", "lastModified": "2026-03-05T22:09:45.190", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-03-04T20:16:19.983", "references": [{"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Mitigation", "Vendor Advisory"], "url": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xvfx-w463-6fpp"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-409"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,0.35.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "cpp-httplib", "source": "cna", "vendor": "yhirose"}, "product": "cpp-httplib", "vendor": "yhirose"}], "analysis": {"en": {"generated_at": "2026-04-16T13:08:05.151614+00:00", "value": {"mitigation_remediation": ["Upgrade cpp-httplib to version 0.35.0 or later where the payload size check is enforced after decompression.", "If upgrading is not possible, add application\u2011level enforcement of a strict payload size limit before decompression or reject requests that exceed a safe threshold, especially when Content\u2011Encoding: gzip is present.", "Monitor HTTP traffic for unusually large compressed payloads and apply network\u2011level rate limiting or connection throttling to mitigate memory exhaustion attempts."], "summary": {"action": "Patch", "impact": "Payload size limit bypass leading to denial of service."}, "threat_synthesis": {"affected_systems": "The vulnerability affects the yhirose:cpp-httplib library, specifically versions prior to 0.35.0. The issue arises in the HandlerWithContentReader use case when Server::set_payload_max_length() is not checked after decompression.", "description_and_impact": "cpp-httplib does not enforce the maximum payload length on a decompressed request body when using streaming ContentReader with Content-Encoding gzip. A small compressed payload can therefore expand beyond the configured limit and be processed by the application, allowing a payload size limit bypass. This flaw can consume excessive CPU or memory, resulting in a denial of service and application unavailability.", "risk_and_exploitability": "With a CVSS score of 7.5, the flaw is considered high severity but the EPSS score is below 1%, indicating a low probability of exploitation at the current time and it is not listed in the KEV catalog. The likely attack vector is remote, through an HTTP(S) request that includes a gzip\u2011encoded payload that, when decompressed, exceeds the application\u2019s configured size limit. An attacker can trigger excessive resource consumption and cause a denial of service."}}}}, "created": "2026-03-05T09:05:47.037592+00:00", "updated": "2026-04-16T13:15:06.225040+00:00", "vendors": ["yhirose", "yhirose$PRODUCT$cpp-httplib"]}