CVE-2026-69206

Http4s: DigestAuth allows replay of captured requests

MEDIUM
5.9
CVSS Score
Published: September 15, 2026 at 07:29 PM UTC
Updated: September 16, 2026 at 08:54 PM UTC
1 product affected across 1 vendorHTTP4S

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.23.35v < 1.0.0-M47
Affected range stops below 0.23.35, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.0.0-M47, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-294

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