CVE-2026-3099
Publication date 12 March 2026
Last updated 18 March 2026
Ubuntu priority
Description
A flaw was found in Libsoup. The server-side digest authentication implementation in the SoupAuthDomainDigest class does not properly track issued nonces or enforce the required incrementing nonce-count (nc) attribute. This vulnerability allows a remote attacker to capture a single valid authentication header and replay it repeatedly. Consequently, the attacker can bypass authentication and gain unauthorized access to protected resources, impersonating the legitimate user.
Read the notes from the security team
Why is this CVE low priority?
Per libsoup developers, impact is quite limited
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| libsoup2.4 | 25.10 questing |
Vulnerable, fix deferred
|
| 24.04 LTS noble |
Vulnerable, fix deferred
|
|
| 22.04 LTS jammy |
Vulnerable, fix deferred
|
|
| 20.04 LTS focal |
Vulnerable, fix deferred
|
|
| 18.04 LTS bionic |
Vulnerable, fix deferred
|
|
| 16.04 LTS xenial |
Vulnerable, fix deferred
|
|
| libsoup3 | 25.10 questing |
Vulnerable, fix deferred
|
| 24.04 LTS noble |
Vulnerable, fix deferred
|
|
| 22.04 LTS jammy |
Vulnerable, fix deferred
|
Notes
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
5.8 · Medium
|
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | Required |
| Scope | Changed |
| Confidentiality | Low |
| Integrity impact | Low |
| Availability impact | Low |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L |