Observable discrepancy in [UNKNOWN] gnutls
Priority LOW 26CWE-203Published · Updated
Key facts
- Attack vector
- Physical
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-203.
Summary
A Bleichenbacher type side-channel based padding oracle attack was found in the way gnutls handles verification of RSA decrypted PKCS#1 v1.5 data. An attacker who is able to run process on the same physical core as the victim process, could use this to extract plaintext or in some cases downgrade any TLS connections to a vulnerable server.
Why it matters now
EPSS 0.00577 47th percentileScored 2026-11-07
Fix Will not fix Red Hat: no fix planned
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| [UNKNOWN] | gnutls | all versions | — | No fix listed | CNA |
- gnutls Vendor[UNKNOWN] Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat Virtualization 4 | Affected | No fix planned: Will not fix |
Not affected: 1 product
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2018-16868
- 2026-10-03 Alias added: GHSA-qjx3-4wr5-3c93
References
More Gnutls vulnerabilities
- TI-2009-03392 The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft… CVSS 3.1CRITICAL 9.8
- TI-2026-03321 Gnutls: gnutls: policy bypass due to case-sensitive nameconstraints comparison CVSS 3.1HIGH 7.4
- TI-2024-00525 Gnutls: rejects certificate chain with distributed trust CVSS 3.1HIGH 7.5
- TI-2023-00345 Observable discrepancy in gnutls CVSS 3.1HIGH 7.4
- TI-2019-02841 Use after free in gnutls CVSS 3.0HIGH 7.5
- TI-2017-03378 Double free vulnerability in the gnutls_x509_ext_import_proxy function in GnuTLS before… CVSS 3.0CRITICAL 9.8
Sources
- CVE-2018-16868 · CVE Program
- CVE-2018-16868 · NVD
- FIRST EPSS
- GHSA-qjx3-4wr5-3c93 · GitHub Advisory Database · CC BY 4.0
- CVE-2018-16868 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences