CVE-2026-69206 Details
Description
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, DigestAuth replay protection records lastNc plus one instead of the highest nonce-count value it has accepted. When a legitimate client sends noncontiguous nc values because of parallel or retried requests, the stored counter remains below the accepted maximum, allowing a passive observer to replay a captured Authorization header multiple times. Successful replays execute authenticated requests, including state-changing operations, as the captured user. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
A vulnerability in http4s versions prior to 0.23.35 and 1.0.0-M47 allows for replay attacks on requests using Digest Authentication. The issue arises because the library's replay protection mechanism incorrectly stores nonce-count values. Instead of keeping the highest accepted nonce-count, it records the last count plus one. This flaw enables a passive observer to replay captured Authorization headers multiple times, executing authenticated requests, including state-changing operations, as the original user.
Users can upgrade to http4s versions 0.23.35 or 1.0.0-M47, both of which include the necessary fix. Instructions for downloading these versions are available on the http4s GitHub releases page.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 15, 2026CISA-ADP
Assessed Sep 16, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/http4s/http4s/commit/7f065101c45f3d86bc105e8fc6323c2c4a11471f | [email protected] | Source CodeVendor |
| https://github.com/http4s/http4s/releases/tag/v0.23.35 | [email protected] | Release NotesVendor |
| https://github.com/http4s/http4s/releases/tag/v1.0.0-M47 | [email protected] | Release NotesVendor |
| https://github.com/http4s/http4s/security/advisories/GHSA-9xww-74xv-gjfp | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-294 | Authentication Bypass by Capture-replay | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| http4s | <= 0.23.34 (semver) >= 1.0.0-M1, <= 1.0.0-M46 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 16, 2026 | CVE Modified | CISA-ADP |
| Sep 15, 2026 | New CVE Received | [email protected] |