Bitwarden Server < 2026.5.0 JSON Injection via Webhook Templates
Bitwarden Server before 2026.5.0 contains a JSON injection vulnerability in IntegrationTemplateProcessor.ReplaceTokens(), which substitutes user-controlled values into event-integration templates without JSON encoding. When an organization has configured an event integration whose template references a user-controlled token (such as #ActingUserName# or #UserName#, populated from a member's display name), an authenticated member can set their display name to JSON metacharacters and inject arbitrary key-value pairs into the rendered payloads delivered to webhook, SIEM, Slack, Teams, or Datadog endpoints, making injected fields indistinguishable from legitimate template output.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-57522
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 05:16 UTC · Revision 1
Source evidence
Bitwarden Server < 2026.5.0 JSON Injection via Webhook Templates
core-osv · Original sourcePublished 25 Jun 2026, 19:09 UTC
Bitwarden Server before 2026.5.0 contains a JSON injection vulnerability in IntegrationTemplateProcessor.ReplaceTokens(), which substitutes user-controlled values into event-integration templates without JSON encoding. When an organization has configured an event integration whose template references a user-controlled token (such as #ActingUserName# or #UserName#, populated from a member's display name), an authenticated member can set their display name to JSON metacharacters and inject arbitrary key-value pairs into the rendered payloads delivered to webhook, SIEM, Slack, Teams, or Datadog endpoints, making injected fields indistinguishable from legitimate template output.
osv:CVE-2026-57522
Complete source record
{
"id": "a6143c826bb399c6278cb91f1a568750ddb15e6d53e43bbf95b7a1a8ad331494",
"url": "https://osv.dev/vulnerability/CVE-2026-57522",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Bitwarden Server < 2026.5.0 JSON Injection via Webhook Templates",
"summary": "Bitwarden Server before 2026.5.0 contains a JSON injection vulnerability in IntegrationTemplateProcessor.ReplaceTokens(), which substitutes user-controlled values into event-integration templates without JSON encoding. When an organization has configured an event integration whose template references a user-controlled token (such as #ActingUserName# or #UserName#, populated from a member's display name), an authenticated member can set their display name to JSON metacharacters and inject arbitrary key-value pairs into the rendered payloads delivered to webhook, SIEM, Slack, Teams, or Datadog endpoints, making injected fields indistinguishable from legitimate template output.",
"evidence": "osv:CVE-2026-57522",
"products": [],
"severity": "low",
"structured": {
"id": "CVE-2026-57522",
"aliases": [
"CVE-2026-57522"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/bitwarden/server",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "c3cabffccfe35004f5022f91f95cc0fb5e8aa7c4"
},
{
"fixed": "a26afd18130ef985ede5c97d277820d045185a28"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:bitwarden:server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "2026.5.0"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "a26afd18130ef985ede5c97d277820d045185a28"
}
],
"source": "REFERENCES_COMMIT"
},
{
"range": [
{
"fixed": "c3cabffccfe35004f5022f91f95cc0fb5e8aa7c4"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v2026.5.0"
}
]
}
}
],
"versions": [
"v2025.10.1",
"v2025.8.1",
"v2025.7.1",
"v2024.10.1",
"v2024.8.1",
"v2024.8.0",
"v2024.5.0",
"v2024.2.3",
"v2024.1.2",
"v1.39.0",
"v1.38.2",
"v1.38.1",
"v1.38.0",
"v1.37.2",
"v1.37.1",
"v1.37.0",
"v1.36.1",
"v1.36.0",
"v1.35.1",
"v1.35.0",
"v1.34.0",
"v1.33.1",
"v1.33.0",
"v1.32.0",
"v1.31.1",
"v1.31.0",
"v1.30.4",
"v1.30.3",
"v1.30.2",
"v1.30.1",
"v1.30.0",
"v1.29.0",
"v1.28.0",
"v1.27.0",
"v1.26.0",
"v1.25.0",
"v1.24.0",
"v1.23.0",
"1.22.0",
"v1.21.0",
"v1.20.0",
"v1.19.0",
"v1.18.0",
"v1.17.2",
"v1.17.1",
"v1.17.0",
"v1.16.0",
"v1.15.1",
"v1.15.0",
"v1.14.2",
"v1.14.1",
"v1.14.0",
"v1.13.1",
"v1.13.0",
"v1.12.1",
"v1.12.0",
"v1.11.1",
"v1.11.0",
"v1.10.0",
"v1.9.0",
"v1.8.2",
"v1.8.1",
"v1.8.0",
"v1.7.0",
"v1.6.0",
"v1.5.1",
"v1.5.0",
"v1.4.1",
"1.4.0",
"v1.3.4",
"v1.3.3",
"v1.3.2",
"v1.3.1",
"v1.3.0",
"v1.2.0",
"v1.1.0",
"v1.0.3",
"v1.0.2",
"v1.0.1",
"v1.0.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-57522.json"
}
}
],
"modified": "2026-10-28T02:30:26.061908592Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57522.json",
"https://github.com/bitwarden/server/releases/tag/v2026.5.0",
"https://nvd.nist.gov/vuln/detail/CVE-2026-57522",
"https://www.vulncheck.com/advisories/bitwarden-server-json-injection-via-webhook-templates",
"https://github.com/bitwarden/server/pull/7593",
"https://github.com/bitwarden/server/commit/a26afd18130ef985ede5c97d277820d045185a28",
"https://github.com/bitwarden/server",
"https://sanjokkarki.com.np/blog/bitwarden-webhook-json-injection"
],
"provider_metadata": {
"cwe_ids": [
"CWE-74"
],
"cna_assigner": "VulnCheck",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57522.json"
}
},
"related_cves": [
{
"value": "CVE-2026-57522",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 492630,
"published_at": "2026-06-25T19:09:33.881+00:00"
}