CVE-2026-33978 (GCVE-0-2026-33978)
Vulnerability from cvelistv5 – Published: 2026-04-01 16:11 – Updated: 2026-04-01 19:07
VLAI?
Title
Notesnook: Stored XSS in mobile share editor via unescaped web clip title metadata
Summary
Notesnook is a note-taking app focused on user privacy & ease of use. Prior to version 3.3.17, a stored XSS vulnerability exists in the mobile share / web clip flow because attacker-controlled clip metadata is concatenated into HTML without escaping and then rendered with innerHTML inside the mobile share editor WebView. An attacker can control the shared title metadata (for example through Android/iOS share metadata such as TITLE / SUBJECT, or through link-preview title data) and inject HTML such as </a><img src=x onerror=...>. When the victim opens the Notesnook share flow and selects Web clip, the payload is inserted into the generated HTML and executed in the mobile editor WebView. This issue has been patched in version 3.3.17.
Severity ?
5.4 (Medium)
CWE
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
| URL | Tags | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| streetwriters | notesnook |
Affected:
< 3.3.17
|
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-33978",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-01T19:07:14.241983Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-01T19:07:24.523Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "notesnook",
"vendor": "streetwriters",
"versions": [
{
"status": "affected",
"version": "\u003c 3.3.17"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Notesnook is a note-taking app focused on user privacy \u0026 ease of use. Prior to version 3.3.17, a stored XSS vulnerability exists in the mobile share / web clip flow because attacker-controlled clip metadata is concatenated into HTML without escaping and then rendered with innerHTML inside the mobile share editor WebView. An attacker can control the shared title metadata (for example through Android/iOS share metadata such as TITLE / SUBJECT, or through link-preview title data) and inject HTML such as \u003c/a\u003e\u003cimg src=x onerror=...\u003e. When the victim opens the Notesnook share flow and selects Web clip, the payload is inserted into the generated HTML and executed in the mobile editor WebView. This issue has been patched in version 3.3.17."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.4,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-79",
"description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-01T16:11:56.610Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/streetwriters/notesnook/security/advisories/GHSA-f27j-fqc6-v7pm",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/streetwriters/notesnook/security/advisories/GHSA-f27j-fqc6-v7pm"
},
{
"name": "https://github.com/streetwriters/notesnook/commit/fc8807f74db5539036c5e58d3d68a11ea54098db",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/streetwriters/notesnook/commit/fc8807f74db5539036c5e58d3d68a11ea54098db"
},
{
"name": "https://github.com/streetwriters/notesnook/releases/tag/3.3.17-android",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/streetwriters/notesnook/releases/tag/3.3.17-android"
}
],
"source": {
"advisory": "GHSA-f27j-fqc6-v7pm",
"discovery": "UNKNOWN"
},
"title": "Notesnook: Stored XSS in mobile share editor via unescaped web clip title metadata"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-33978",
"datePublished": "2026-04-01T16:11:56.610Z",
"dateReserved": "2026-03-24T22:20:06.210Z",
"dateUpdated": "2026-04-01T19:07:24.523Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-33978\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-04-01T17:28:39.660\",\"lastModified\":\"2026-04-03T16:11:11.357\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Notesnook is a note-taking app focused on user privacy \u0026 ease of use. Prior to version 3.3.17, a stored XSS vulnerability exists in the mobile share / web clip flow because attacker-controlled clip metadata is concatenated into HTML without escaping and then rendered with innerHTML inside the mobile share editor WebView. An attacker can control the shared title metadata (for example through Android/iOS share metadata such as TITLE / SUBJECT, or through link-preview title data) and inject HTML such as \u003c/a\u003e\u003cimg src=x onerror=...\u003e. When the victim opens the Notesnook share flow and selects Web clip, the payload is inserted into the generated HTML and executed in the mobile editor WebView. This issue has been patched in version 3.3.17.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N\",\"baseScore\":5.4,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":2.8,\"impactScore\":2.5}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-79\"}]}],\"references\":[{\"url\":\"https://github.com/streetwriters/notesnook/commit/fc8807f74db5539036c5e58d3d68a11ea54098db\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/streetwriters/notesnook/releases/tag/3.3.17-android\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/streetwriters/notesnook/security/advisories/GHSA-f27j-fqc6-v7pm\",\"source\":\"security-advisories@github.com\"}]}}",
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-33978\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-04-01T19:07:14.241983Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-04-01T19:07:21.163Z\"}}], \"cna\": {\"title\": \"Notesnook: Stored XSS in mobile share editor via unescaped web clip title metadata\", \"source\": {\"advisory\": \"GHSA-f27j-fqc6-v7pm\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 5.4, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"REQUIRED\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"LOW\"}}], \"affected\": [{\"vendor\": \"streetwriters\", \"product\": \"notesnook\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 3.3.17\"}]}], \"references\": [{\"url\": \"https://github.com/streetwriters/notesnook/security/advisories/GHSA-f27j-fqc6-v7pm\", \"name\": \"https://github.com/streetwriters/notesnook/security/advisories/GHSA-f27j-fqc6-v7pm\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/streetwriters/notesnook/commit/fc8807f74db5539036c5e58d3d68a11ea54098db\", \"name\": \"https://github.com/streetwriters/notesnook/commit/fc8807f74db5539036c5e58d3d68a11ea54098db\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/streetwriters/notesnook/releases/tag/3.3.17-android\", \"name\": \"https://github.com/streetwriters/notesnook/releases/tag/3.3.17-android\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Notesnook is a note-taking app focused on user privacy \u0026 ease of use. Prior to version 3.3.17, a stored XSS vulnerability exists in the mobile share / web clip flow because attacker-controlled clip metadata is concatenated into HTML without escaping and then rendered with innerHTML inside the mobile share editor WebView. An attacker can control the shared title metadata (for example through Android/iOS share metadata such as TITLE / SUBJECT, or through link-preview title data) and inject HTML such as \u003c/a\u003e\u003cimg src=x onerror=...\u003e. When the victim opens the Notesnook share flow and selects Web clip, the payload is inserted into the generated HTML and executed in the mobile editor WebView. This issue has been patched in version 3.3.17.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-79\", \"description\": \"CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-04-01T16:11:56.610Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-33978\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-04-01T19:07:24.523Z\", \"dateReserved\": \"2026-03-24T22:20:06.210Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-04-01T16:11:56.610Z\", \"assignerShortName\": \"GitHub_M\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
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…
Loading…