CVE-2026-57522

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.

CVSS 4.0

2.3CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N

CVSS 3.1

5.0CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N

EPSS

0.5% chance of exploitation in the next 30 days; higher than 39% of CVEs (scores of 2026-10-25)

CWE

CWE-74

Published

2026-06-25

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

Affected

• bitwarden:server

References

• https://github.com/bitwarden/server/commit/a26afd18130ef985ede5c97d277820d045185a28
• https://github.com/bitwarden/server/pull/7593
• https://github.com/bitwarden/server/releases/tag/v2026.5.0
• https://sanjokkarki.com.np/blog/bitwarden-webhook-json-injection
• https://www.vulncheck.com/advisories/bitwarden-server-json-injection-via-webhook-templates

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