{"id":"CVE-2026-100863","state":"PUBLISHED","title":"Heym before 0.0.91 SSRF via image fetching and IPv6 validation","description":"Heym versions 0.0.90 and earlier contain two server-side request forgery (SSRF) egress gaps, both remediated in app/services/ssrf_guard.py in 0.0.91. First, the LLM image-edit input loader (_load_image_bytes) fetched caller-controlled HTTP/HTTPS URLs with a bare httpx.get, applying only a scheme check and bypassing the egress-pinning HTTP client; because the workflow DSL supports \"imageInput\": \"$userInput.body.imageUrl\", a webhook or API caller can choose the fetch target when a workflow author uses that expression, allowing requests to loopback, RFC1918, and cloud metadata endpoints. Second, _is_public_address unwrapped only IPv4-mapped IPv6 addresses, so IPv6 transition forms — the NAT64 well-known prefix 64:ff9b::/96, deprecated IPv4-compatible ::x.x.x.x addresses, and 6to4 (2002::/16, classified as globally routable by Python 3.11.0 through 3.11.9) — could carry loopback, RFC1918, link-local, or cloud-metadata IPv4 destinations past both the initial URL validation and the dial-time IP pin. Version 0.0.91 routes the image loader through guard_http_url and the guarded client, evaluates NAT64 and IPv4-compatible addresses by their embedded IPv4 address, and refuses 64:ff9b:1::/48, 6to4, and Teredo (2001::/32) outright.","publishedAt":"2026-09-27T01:28:52.561Z","updatedAt":"2026-09-30T15:24:03.334Z","severity":{"score":5.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["heymrun heym"],"affected":[{"vendor":"heymrun","product":"heym","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"0.0.91","versionType":"semver"},{"version":"0.0.91","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/heymrun/heym/security/advisories/GHSA-6rph-qqcv-jqh4","https://www.vulncheck.com/advisories/heym-before-0.0.91-ssrf-via-image-fetching-and-ipv6-validation"],"weaknesses":["CWE-918"],"ingestedAt":"2026-10-29T20:10:13.529Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/100xxx/CVE-2026-100863.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-100863","state":"PUBLISHED","datePublished":"2026-09-27T01:28:52.561Z","dateUpdated":"2026-09-30T15:24:03.334Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-09-27T00:20:54.407Z"},"containers":{"cna":{"title":"Heym before 0.0.91 SSRF via image fetching and IPv6 validation","descriptions":[{"lang":"en","value":"Heym versions 0.0.90 and earlier contain two server-side request forgery (SSRF) egress gaps, both remediated in app/services/ssrf_guard.py in 0.0.91. First, the LLM image-edit input loader (_load_image_bytes) fetched caller-controlled HTTP/HTTPS URLs with a bare httpx.get, applying only a scheme check and bypassing the egress-pinning HTTP client; because the workflow DSL supports \"imageInput\": \"$userInput.body.imageUrl\", a webhook or API caller can choose the fetch target when a workflow author uses that expression, allowing requests to loopback, RFC1918, and cloud metadata endpoints. Second, _is_public_address unwrapped only IPv4-mapped IPv6 addresses, so IPv6 transition forms — the NAT64 well-known prefix 64:ff9b::/96, deprecated IPv4-compatible ::x.x.x.x addresses, and 6to4 (2002::/16, classified as globally routable by Python 3.11.0 through 3.11.9) — could carry loopback, RFC1918, link-local, or cloud-metadata IPv4 destinations past both the initial URL validation and the dial-time IP pin. Version 0.0.91 routes the image loader through guard_http_url and the guarded client, evaluates NAT64 and IPv4-compatible addresses by their embedded IPv4 address, and refuses 64:ff9b:1::/48, 6to4, and Teredo (2001::/32) outright."}],"affected":[{"vendor":"heymrun","product":"heym","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"0.0.91","versionType":"semver"},{"version":"0.0.91","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/heymrun/heym/security/advisories/GHSA-6rph-qqcv-jqh4","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-6rph-qqcv-jqh4)"},{"url":"https://www.vulncheck.com/advisories/heym-before-0.0.91-ssrf-via-image-fetching-and-ipv6-validation","name":"VulnCheck Advisory: Heym before 0.0.91 SSRF via image fetching and IPv6 validation","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE","baseScore":5,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"Server-Side Request Forgery (SSRF)","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-09-27T01:28:52.561Z"},"datePublic":"2026-08-15T00:00:00.000Z","x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-30T15:23:50.708780Z","id":"CVE-2026-100863","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-30T15:24:03.334Z"}}]}}}