CVE-2026-3099Libsoup: libsoup: authentication bypass via digest authentication replay attack
- 5.8MediumCVSS base score
- 0.42%Exploitation in 30 daysEPSS · top 63% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By redhat
- 16 days later
· 16 days later
Published
- 8 months later
· 8 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | Medium5.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L |
| NVDNVD · Analyzed | 3.1 | High7.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
- EPSS (exploitation in 30 days)
- 0.42% · top 63% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.8.
Affected products
Red Hat · Red Hat Enterprise Linux 10
All versions: unaffected
Red Hat · Red Hat Enterprise Linux 6
All versions: unknown
Red Hat · Red Hat Enterprise Linux 7
All versions: unaffected
Red Hat · Red Hat Enterprise Linux 8
All versions: unaffected
Red Hat · Red Hat Enterprise Linux 9
All versions: unaffected
What to do
Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
References
References3
- https://access.redhat.com/security/cve/CVE-2026-3099 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2442232 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/495 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-11573 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-3099)Record last updated .