Medium severity · published Jun 25, 2026
CVE-2026-57522
Bitwarden Server < 2026.5.0 JSON Injection via Webhook Templates
5.0
CVSS
0.5%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 39% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SE
server · bitwarden
before 2026.5.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-57522
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-57522
Patch
https://github.com/bitwarden/server/commit/a26afd18130ef985ede5c97d277820d045185a28
Issue Tracking
https://github.com/bitwarden/server/pull/7593
Release Notes
https://github.com/bitwarden/server/releases/tag/v2026.5.0
Exploit
https://sanjokkarki.com.np/blog/bitwarden-webhook-json-injection
Third Party Advisory
https://www.vulncheck.com/advisories/bitwarden-server-json-injection-via-webhook-templates
More from server
9.1
CVE-2026-43639
Bitwarden Server < 2026.4.0 Missing Authorization via Provider Clients
8.1
CVE-2026-43640
Bitwarden Server < 2026.4.1 Authentication Bypass via SCIM API Key
8.0
CVE-2026-60104
Bitwarden Server < 2026.6.0 Authorization Bypass via Admin Auth Request
7.5
CVE-2020-15879
Bitwarden Server 1.35.1 allows SSRF because it does not consider certain IPv6 addresses (ones beginning with fc, fd, fe, or ff, and the :: address) and certain IPv4 addresses…
7.5
CVE-2019-19766
The Bitwarden server through 1.32.0 has a potentially unwanted KDF