env-set cross-proxy Digest auth state leak
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Partial Red Hat: 14 fixed, 8 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-294.
Summary
When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests. Specifically, if the initial transfer authenticates against `proxyA` using Digest auth, a subsequent transfer routed through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended solely for `proxyA`.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| curl | curl | 7.12.0 to before 8.14.2; 8.15.0 to before 8.16.1; 8.17.0 to before 8.20.1 | 8.14.2, 8.16.1, 8.20.1 | Patch available | CNA |
| curl | curl | 8.20.0; 8.19.0; 8.18.0; 8.17.0; 8.16.0; 8.15.0; 8.14.1; 8.14.0; 8.13.0; 8.12.1; 8.12.0; 8.11.1; 8.11.0; 8.10.1; 8.10.0; 8.9.1; 8.9.0; 8.8.0; 8.7.1; 8.7.0; 8.6.0; 8.5.0; 8.4.0; 8.3.0; 8.2.1; 8.2.0; 8.1.2; 8.1.1; 8.1.0; 8.0.1; 8.0.0; 7.88.1; 7.88.0; 7.87.0; 7.86.0; 7.85.0; 7.84.0; 7.83.1; 7.83.0; 7.82.0; 7.81.0; 7.80.0; 7.79.1; 7.79.0; 7.78.0; 7.77.0; 7.76.1; 7.76.0; 7.75.0; 7.74.0; 7.73.0; 7.72.0; 7.71.1; 7.71.0; 7.70.0; 7.69.1; 7.69.0; 7.68.0; 7.67.0; 7.66.0; 7.65.3; 7.65.2; 7.65.1; 7.65.0; 7.64.1; 7.64.0; 7.63.0; 7.62.0; 7.61.1; 7.61.0; 7.60.0; 7.59.0; 7.58.0; 7.57.0; 7.56.1; 7.56.0; 7.55.1; 7.55.0; 7.54.1; 7.54.0; 7.53.1; 7.53.0; 7.52.1; 7.52.0; 7.51.0; 7.50.3; 7.50.2; 7.50.1; 7.50.0; 7.49.1; 7.49.0; 7.48.0; 7.47.1; 7.47.0; 7.46.0; 7.45.0; 7.44.0; 7.43.0; 7.42.1; 7.42.0; 7.41.0; 7.40.0; 7.39.0; 7.38.0; 7.37.1; 7.37.0; 7.36.0; 7.35.0; 7.34.0; 7.33.0; 7.32.0; 7.31.0; 7.30.0; 7.29.0; 7.28.1; 7.28.0; 7.27.0; 7.26.0; 7.25.0; 7.24.0; 7.23.1; 7.23.0; 7.22.0; 7.21.7; 7.21.6; 7.21.5; 7.21.4; 7.21.3; 7.21.2; 7.21.1; 7.21.0; 7.20.1; 7.20.0; 7.19.7; 7.19.6; 7.19.5; 7.19.4; 7.19.3; 7.19.2; 7.19.1; 7.19.0; 7.18.2; 7.18.1; 7.18.0; 7.17.1; 7.17.0; 7.16.4; 7.16.3; 7.16.2; 7.16.1; 7.16.0; 7.15.5; 7.15.4; 7.15.3; 7.15.2; 7.15.1; 7.15.0; 7.14.1; 7.14.0; 7.13.2; 7.13.1; 7.13.0; 7.12.3; 7.12.2; 7.12.1; 7.12.0 | — | No fix listed | CNA |
- curl Vendorcurl Affected 7.12.0 to before 8.14.2; 8.15.0 to before 8.16.1; 8.17.0 to before 8.20.1 Fixed in 8.14.2, 8.16.1, 8.20.1 Patch available CNA
- curl Vendorcurl Affected 8.20.0; 8.19.0; 8.18.0; 8.17.0; 8.16.0; 8.15.0; 8.14.1; 8.14.0; 8.13.0; 8.12.1; 8.12.0; 8.11.1; 8.11.0; 8.10.1; 8.10.0; 8.9.1; 8.9.0; 8.8.0; 8.7.1; 8.7.0; 8.6.0; 8.5.0; 8.4.0; 8.3.0; 8.2.1; 8.2.0; 8.1.2; 8.1.1; 8.1.0; 8.0.1; 8.0.0; 7.88.1; 7.88.0; 7.87.0; 7.86.0; 7.85.0; 7.84.0; 7.83.1; 7.83.0; 7.82.0; 7.81.0; 7.80.0; 7.79.1; 7.79.0; 7.78.0; 7.77.0; 7.76.1; 7.76.0; 7.75.0; 7.74.0; 7.73.0; 7.72.0; 7.71.1; 7.71.0; 7.70.0; 7.69.1; 7.69.0; 7.68.0; 7.67.0; 7.66.0; 7.65.3; 7.65.2; 7.65.1; 7.65.0; 7.64.1; 7.64.0; 7.63.0; 7.62.0; 7.61.1; 7.61.0; 7.60.0; 7.59.0; 7.58.0; 7.57.0; 7.56.1; 7.56.0; 7.55.1; 7.55.0; 7.54.1; 7.54.0; 7.53.1; 7.53.0; 7.52.1; 7.52.0; 7.51.0; 7.50.3; 7.50.2; 7.50.1; 7.50.0; 7.49.1; 7.49.0; 7.48.0; 7.47.1; 7.47.0; 7.46.0; 7.45.0; 7.44.0; 7.43.0; 7.42.1; 7.42.0; 7.41.0; 7.40.0; 7.39.0; 7.38.0; 7.37.1; 7.37.0; 7.36.0; 7.35.0; 7.34.0; 7.33.0; 7.32.0; 7.31.0; 7.30.0; 7.29.0; 7.28.1; 7.28.0; 7.27.0; 7.26.0; 7.25.0; 7.24.0; 7.23.1; 7.23.0; 7.22.0; 7.21.7; 7.21.6; 7.21.5; 7.21.4; 7.21.3; 7.21.2; 7.21.1; 7.21.0; 7.20.1; 7.20.0; 7.19.7; 7.19.6; 7.19.5; 7.19.4; 7.19.3; 7.19.2; 7.19.1; 7.19.0; 7.18.2; 7.18.1; 7.18.0; 7.17.1; 7.17.0; 7.16.4; 7.16.3; 7.16.2; 7.16.1; 7.16.0; 7.15.5; 7.15.4; 7.15.3; 7.15.2; 7.15.1; 7.15.0; 7.14.1; 7.14.0; 7.13.2; 7.13.1; 7.13.0; 7.12.3; 7.12.2; 7.12.1; 7.12.0 Fixed in — No fix listed CNA
Remediation
- Fix · CNA curl (curl) Fixed in 8.14.2, 8.16.1, 8.20.1
Red Hat 16 advisories
- RHSA-2026:93454 Released 2026-11-02 · Red Hat rating Importantcurl security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) libcurl-devel-7.76.1-31.el9_6.4
- Red Hat Enterprise Linux BaseOS EUS (v.9.6) curl-7.76.1-31.el9_6.4, curl-minimal-7.76.1-31.el9_6.4, libcurl-7.76.1-31.el9_6.4 +1
- RHSA-2026:92368 Released 2026-10-29 · Red Hat rating Importantcurl security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) curl-7.61.1-34.el8_10.18, libcurl-7.61.1-34.el8_10.18, libcurl-devel-7.61.1-34.el8_10.18 +1
- RHSA-2026:73516 Released 2026-09-29 · Red Hat rating ImportantRed Hat OpenShift Dev Spaces 3.30.2 Release.
- Red Hat OpenShift Dev Spaces 3.30 registry.redhat.io/devspaces/code-rhel9
Show 13 more Red Hat advisories
- RHSA-2026:72506 Released 2026-09-28 · Red Hat rating Importantcurl security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) libcurl-devel-8.12.1-1.el10_0.10
- Red Hat Enterprise Linux BaseOS EUS (v. 10.0) curl-8.12.1-1.el10_0.10, libcurl-8.12.1-1.el10_0.10, libcurl-minimal-8.12.1-1.el10_0.10
- RHSA-2026:72476 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
- RHSA-2026:72475 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
- RHSA-2026:72470 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
- RHSA-2026:72399 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
- RHSA-2026:72395 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
- RHSA-2026:72394 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
- RHSA-2026:71603 Released 2026-09-24 · Red Hat rating ImportantRed Hat Update Infrastructure 5.3 security update
- Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-rhel9, registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9 +2
- RHSA-2026:69126 Released 2026-09-21 · Red Hat rating Importantcurl security update
- Red Hat Enterprise Linux AppStream (v. 9) libcurl-devel-7.76.1-40.el9_8.7
- Red Hat Enterprise Linux BaseOS (v. 9) curl-7.76.1-40.el9_8.7, curl-minimal-7.76.1-40.el9_8.7, libcurl-7.76.1-40.el9_8.7 +1
- RHSA-2026:56869 Released 2026-08-19 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.62 SP5 security update
- Red Hat JBoss Core Services 2.4.62.SP5
- RHSA-2026:55432 Released 2026-08-17 · Red Hat rating Importantcurl security update
- Red Hat Enterprise Linux AppStream (v. 10) libcurl-devel-8.12.1-4.el10_2.4
- Red Hat Enterprise Linux BaseOS (v. 10) curl-8.12.1-4.el10_2.4, libcurl-8.12.1-4.el10_2.4, libcurl-minimal-8.12.1-4.el10_2.4
- RHSA-2026:34975 Released 2026-07-02 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images cargo-1.96.1-1.hum1@aarch64, cargo-1.96.1-1.hum1@x86_64, clippy-1.96.1-1.hum1@aarch64 +36
- RHSA-2026:29017 Released 2026-06-24 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images curl-8.21.0-0.1.hum1@aarch64, curl-8.21.0-0.1.hum1@src, curl-8.21.0-0.1.hum1@x86_64 +6
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
curl 8.14.2, 8.16.1, 8.20.1
13 records Highest priority Priority HIGH 12 HIGH, 1 MEDIUM
Other records, highest priority first
- TI-2026-10231 cross-origin Digest auth state leakPriority HIGH 82
- TI-2026-09063 HTTP/2 stream-dependency tree UAFPriority HIGH 82
- TI-2026-07976 stale proxy password leakPriority HIGH 82
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Confidential Compute Attestation | Affected | No fix yet |
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix yet |
| Red Hat JBoss Core Services | Affected | No fix planned: Will not fix |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Cert Manager support for Red Hat OpenShift release 1.20 | Fixed | RHSA-2026:72394, RHSA-2026:72395, RHSA-2026:72399, RHSA-2026:72470, RHSA-2026:72475, RHSA-2026:72476 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:55432 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:69126 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:72506 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:93454 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:55432 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:92368 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:69126 |
| Red Hat Enterprise Linux BaseOS EUS (v. 10.0) | Fixed | RHSA-2026:72506 |
| Red Hat Enterprise Linux BaseOS EUS (v.9.6) | Fixed | RHSA-2026:93454 |
| Red Hat Hardened Images | Fixed | RHSA-2026:29017, RHSA-2026:34975 |
| Red Hat JBoss Core Services 2.4.62.SP5 | Fixed | RHSA-2026:56869 |
| Red Hat OpenShift Dev Spaces 3.30 | Fixed | RHSA-2026:73516 |
| Red Hat Update Infrastructure 5 | Fixed | RHSA-2026:71603 |
Not affected: 7 products
- Cert Manager support for Red Hat OpenShift release 1.20
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift AI (RHOAI)
- Red Hat OpenShift Container Platform 5
- Red Hat OpenShift Dev Spaces 3.30
- Red Hat Trusted Profile Analyzer
Timeline
- 2026-10-02 Threatist record created from CVE-2026-8927
- 2026-10-03 Alias added: GHSA-jr4f-4564-w3mr
- 2026-10-09 Fix available: RHSA-2026:56869 · Red Hat
- 2026-10-10 Fix available: Red Hat JBoss Core Services 2.4.62.SP5 · Red Hat
- 2026-10-29 Fix available: RHSA-2026:92368 · Red Hat
- 2026-10-29 Fix available: Red Hat Enterprise Linux BaseOS (v. 8) · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
- 2026-11-02 Fix available: RHSA-2026:93454 · Red Hat
- 2026-11-02 Fix available: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6) · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
More curl vulnerabilities
- TI-2023-19922 Out-of-bounds write in curl CVSS 3.1CRITICAL 9.8
- TI-2026-16162 Negotiate ambient user conn reuse CVSS 3.1CRITICAL 9.8
- TI-2026-10231 cross-origin Digest auth state leak CVSS 3.1CRITICAL 9.8
- TI-2026-09063 HTTP/2 stream-dependency tree UAF CVSS 3.1CRITICAL 9.8
- TI-2026-07976 stale proxy password leak CVSS 3.1CRITICAL 9.8
- TI-2026-07845 SASL double-free CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-8927 · CVE Program
- CVE-2026-8927 · NVD
- FIRST EPSS
- GHSA-jr4f-4564-w3mr · GitHub Advisory Database · CC BY 4.0
- CVE-2026-8927 · 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