An issue was discovered in Istio 1.3 through 1.3.6.
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
An issue was discovered in Istio 1.3 through 1.3.6. Under certain circumstances, it is possible to bypass a specifically configured Mixer policy. Istio-proxy accepts the x-istio-attributes header at ingress that can be used to affect policy decisions when Mixer policy selectively applies to a source equal to ingress. To exploit this vulnerability, someone has to encode a source.uid in this header. This feature is disabled by default in Istio 1.3 and 1.4.
Why it matters now
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 |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2020-8843
- 2026-10-03 Alias added: GHSA-8hpm-7f4v-97xg
References
More Istio vulnerabilities
- TI-2026-79288 Out-of-bounds write in Google Brotli decoder KEVCVSS 4.0CRITICAL 9.2
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2022-06055 Authorization Policy bypass in Istio CVSS 3.1CRITICAL 9.8
- TI-2021-11909 Istio before 1.8.6 and 1.9.x before 1.9.5 contains a remotely exploitable vulnerability… CVSS 3.1CRITICAL 9.8
- TI-2026-24390 Istio JWKS resolver to prevent private key material from being exposed when JWKS fetch fails. CVSS 4.0HIGH 8.7
- TI-2022-13090 Ill-formed headers may lead to unexpected behavior in Istio CVSS 3.1CRITICAL 9.8
Sources
- CVE-2020-8843 · CVE Program
- CVE-2020-8843 · NVD
- FIRST EPSS
- GHSA-8hpm-7f4v-97xg · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences