CVE-2026-48087 (GCVE-0-2026-48087)
Vulnerability from cvelistv5 – Published: 2026-08-06 21:32 – Updated: 2026-08-07 17:08
VLAI
EPSS
VEX
Title
OpenReception: WebAuthn passkey injection allows account takeover
Summary
OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.2, the registration handler at `POST /api/auth/register/{userId}` validates the relationship between the WebAuthn challenge and the registration cookie's email but never validates that the `userId` in the URL belongs to that email. An unauthenticated attacker requests a challenge for their own email, generates a registration response with their own authenticator, and submits it against any victim user's URL. The challenge-vs-cookie email match passes, the WebAuthn ceremony validates, and `addPasskey` writes the attacker's credential into the victim's `user_passkey` rows. The next victim-email login accepts a passkey assertion from the attacker's authenticator and issues a session as the victim. User IDs are not strictly secret on this platform, but the exact set of exposure surfaces should be assessed by the maintainers. Staff-list endpoints return user IDs to authenticated tenant members per the route signature; live verification of all exposure surfaces (whether user IDs leak through any unauthenticated route, through invite-confirmation URLs, or through other administrative views) is part of the pending live PoC. Where the attacker knows the victim's email and userId, the analysis below becomes account takeover. Version 1.0.2 fixes the issue.
Severity
9.8 (Critical)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
- CWE-287 - Improper Authentication
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/open-reception/appointment-boo… | x_refsource_CONFIRM |
| https://github.com/open-reception/appointment-boo… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| open-reception | appointment-booking-software |
Affected:
< 1.0.2
|
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-48087",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-07T14:53:40.729550Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-07T17:08:39.347Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "appointment-booking-software",
"vendor": "open-reception",
"versions": [
{
"status": "affected",
"version": "\u003c 1.0.2"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "OpenReception\u0027s appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.2, the registration handler at `POST /api/auth/register/{userId}` validates the relationship between the WebAuthn challenge and the registration cookie\u0027s email but never validates that the `userId` in the URL belongs to that email. An unauthenticated attacker requests a challenge for their own email, generates a registration response with their own authenticator, and submits it against any victim user\u0027s URL. The challenge-vs-cookie email match passes, the WebAuthn ceremony validates, and `addPasskey` writes the attacker\u0027s credential into the victim\u0027s `user_passkey` rows. The next victim-email login accepts a passkey assertion from the attacker\u0027s authenticator and issues a session as the victim. User IDs are not strictly secret on this platform, but the exact set of exposure surfaces should be assessed by the maintainers. Staff-list endpoints return user IDs to authenticated tenant members per the route signature; live verification of all exposure surfaces (whether user IDs leak through any unauthenticated route, through invite-confirmation URLs, or through other administrative views) is part of the pending live PoC. Where the attacker knows the victim\u0027s email and userId, the analysis below becomes account takeover. Version 1.0.2 fixes the issue."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-287",
"description": "CWE-287: Improper Authentication",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-06T21:32:30.560Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-j9rw-x2wv-h5rj",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-j9rw-x2wv-h5rj"
},
{
"name": "https://github.com/open-reception/appointment-booking-software/commit/5f61a2116d68378366edd712c343a9de7b205a74",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/open-reception/appointment-booking-software/commit/5f61a2116d68378366edd712c343a9de7b205a74"
}
],
"source": {
"advisory": "GHSA-j9rw-x2wv-h5rj",
"discovery": "UNKNOWN"
},
"title": "OpenReception: WebAuthn passkey injection allows account takeover"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-48087",
"datePublished": "2026-08-06T21:32:30.560Z",
"dateReserved": "2026-05-20T18:40:45.833Z",
"dateUpdated": "2026-08-07T17:08:39.347Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-48087",
"date": "2026-08-11",
"epss": "0.00457",
"percentile": "0.37557"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2026-48087\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-08-06T22:17:11.750\",\"lastModified\":\"2026-08-07T18:17:18.303\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"OpenReception\u0027s appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.2, the registration handler at `POST /api/auth/register/{userId}` validates the relationship between the WebAuthn challenge and the registration cookie\u0027s email but never validates that the `userId` in the URL belongs to that email. An unauthenticated attacker requests a challenge for their own email, generates a registration response with their own authenticator, and submits it against any victim user\u0027s URL. The challenge-vs-cookie email match passes, the WebAuthn ceremony validates, and `addPasskey` writes the attacker\u0027s credential into the victim\u0027s `user_passkey` rows. The next victim-email login accepts a passkey assertion from the attacker\u0027s authenticator and issues a session as the victim. User IDs are not strictly secret on this platform, but the exact set of exposure surfaces should be assessed by the maintainers. Staff-list endpoints return user IDs to authenticated tenant members per the route signature; live verification of all exposure surfaces (whether user IDs leak through any unauthenticated route, through invite-confirmation URLs, or through other administrative views) is part of the pending live PoC. Where the attacker knows the victim\u0027s email and userId, the analysis below becomes account takeover. Version 1.0.2 fixes the issue.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"open-reception\",\"product\":\"appointment-booking-software\",\"versions\":[{\"version\":\"\u003c 1.0.2\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":9.8,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":5.9}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-08-07T14:53:40.729550Z\",\"id\":\"CVE-2026-48087\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"yes\"},{\"technicalImpact\":\"total\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-287\"}]}],\"references\":[{\"url\":\"https://github.com/open-reception/appointment-booking-software/commit/5f61a2116d68378366edd712c343a9de7b205a74\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-j9rw-x2wv-h5rj\",\"source\":\"security-advisories@github.com\"}]}}",
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-48087\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-08-07T14:53:40.729550Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-08-07T14:53:44.562Z\"}}], \"cna\": {\"title\": \"OpenReception: WebAuthn passkey injection allows account takeover\", \"source\": {\"advisory\": \"GHSA-j9rw-x2wv-h5rj\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 9.8, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"CRITICAL\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"vendor\": \"open-reception\", \"product\": \"appointment-booking-software\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 1.0.2\"}]}], \"references\": [{\"url\": \"https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-j9rw-x2wv-h5rj\", \"name\": \"https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-j9rw-x2wv-h5rj\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/open-reception/appointment-booking-software/commit/5f61a2116d68378366edd712c343a9de7b205a74\", \"name\": \"https://github.com/open-reception/appointment-booking-software/commit/5f61a2116d68378366edd712c343a9de7b205a74\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"OpenReception\u0027s appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.2, the registration handler at `POST /api/auth/register/{userId}` validates the relationship between the WebAuthn challenge and the registration cookie\u0027s email but never validates that the `userId` in the URL belongs to that email. An unauthenticated attacker requests a challenge for their own email, generates a registration response with their own authenticator, and submits it against any victim user\u0027s URL. The challenge-vs-cookie email match passes, the WebAuthn ceremony validates, and `addPasskey` writes the attacker\u0027s credential into the victim\u0027s `user_passkey` rows. The next victim-email login accepts a passkey assertion from the attacker\u0027s authenticator and issues a session as the victim. User IDs are not strictly secret on this platform, but the exact set of exposure surfaces should be assessed by the maintainers. Staff-list endpoints return user IDs to authenticated tenant members per the route signature; live verification of all exposure surfaces (whether user IDs leak through any unauthenticated route, through invite-confirmation URLs, or through other administrative views) is part of the pending live PoC. Where the attacker knows the victim\u0027s email and userId, the analysis below becomes account takeover. Version 1.0.2 fixes the issue.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-287\", \"description\": \"CWE-287: Improper Authentication\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-08-06T21:32:30.560Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-48087\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-07T17:08:39.347Z\", \"dateReserved\": \"2026-05-20T18:40:45.833Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-08-06T21:32:30.560Z\", \"assignerShortName\": \"GitHub_M\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
Loading…
Loading…