CVE-2026-116678

MEDIUM
Published Oct 27, 2026 Modified Oct 30, 2026 CWE-918

Description

Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to version 1.37.0, the Vaultwarden icon downloader validates the initial icon host and DNS results but passes favicon URLs parsed from attacker-controlled HTML to get_page_with_referer() without applying should_block_host() to the second-stage host. This flaw bypasses the remediation for CVE-2026-47160, which covered decimal, hexadecimal, octal, and IPv4-mapped IPv6 host normalization, because the second-stage IP-literal favicon fetch does not invoke the custom DNS resolver. A remote unauthenticated attacker can provide a public page whose favicon uses an IP-literal URL, allowing the Vaultwarden server to reach loopback or private and internal addresses. The issue affects instances with internal icon downloading enabled and can expose internal responses that resemble supported images or reveal reachability through timing, status, and cache behavior. This issue is fixed in version 1.37.0.

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CVSS v3.1 Score

5.8
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0033
Probability of exploitation
0.26%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-918 Server-Side Request Forgery (SSRF)

References

Frequently Asked Questions

What is CVE-2026-116678? +
Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to version 1.37.0, the Vaultwarden icon downloader validates the initial icon host and DNS results but passes favicon URLs parsed from attacker-controlled HTML to get_page_with_referer() without applying should_block_host() to the second-stage host. This flaw bypasses the remediation for CVE-2026-47160, which covered decimal, hexadecimal, octal, and IPv4-mapped IPv6 host normalization, because the second-stage IP-literal favicon fetch does not invoke the custom DNS resolver. A remote unauthenticated attacker can provide a public page whose favicon uses an IP-literal URL, allowing the Vaultwarden server to reach loopback or private and internal addresses. The issue affects instances with internal icon downloading enabled and can expose internal responses that resemble supported images or reveal reachability through timing, status, and cache behavior. This issue is fixed in version 1.37.0. It has a CVSS v3.1 base score of 5.8 (MEDIUM).
How severe is CVE-2026-116678? +
CVE-2026-116678 has a CVSS v3.1 score of 5.8 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0033, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-116678? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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