What is CVE-2026-57522?

CVE-2026-57522 is a low-severity vulnerability in Bitwarden Server, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 3.5/10. Published 2026-06-25.

How severe is CVE-2026-57522?

Low severity. CVSS v3 base score is 3.5 out of 10.

Vulnerability in Bitwarden Server

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.

Published 2026-06-25 · last modified 2026-07-14.

CVSS v3 metric

CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.005 (38.8th percentile), scored 2026-09-24.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Bitwarden Server — versions 0

Weakness classification (CWE)

CWE-74 — Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection)

References

sanjokkarki.com.np/blog/bitwarden-webhook-json-injection (Exploit, technical-description, Patch, Third Party Advisory, exploit)
github.com/bitwarden/server/releases/tag/v2026.5.0 (release-notes, Release Notes)
github.com/bitwarden/server/pull/7593 (issue-tracking, Issue Tracking)
github.com/bitwarden/server/commit/a26afd18130ef985ede5c97d277820d045185a28 (Patch, patch)
www.vulncheck.com/advisories/bitwarden-server-json-injection-via-webhook-templa… (Third Party Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-57522?: CVE-2026-57522 is a low-severity vulnerability in Bitwarden Server, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 3.5/10. Published 2026-06-25.
How severe is CVE-2026-57522?: Low severity. CVSS v3 base score is 3.5 out of 10.