curl reuses connections with the wrong local source address
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 1 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
curl versions 8.9.0, 8.9.1, 8.10.0, 8.10.1, 8.11.0, 8.11.1, 8.12.0, 8.12.1, 8.13.0, 8.14.0, 8.14.1, 8.15.0, 8.16.0, 8.17.0, 8.18.0, 8.19.0, 8.20.0, 8.21.0 and 8.22.0 are affected. With one of the documented CURLOPT_INTERFACE prefixes, the binding is left out of the connection reuse key, so a later transfer can silently reuse a connection and use the earlier transfer's source address. The CVSS vector describes a remote, high complexity attack that needs no privileges or user interaction.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
When `CURLOPT_INTERFACE` (or the command line tool's `--interface` option) is set with one of the documented prefixes (`if!`, `host!`, `ifhost!`), that binding is not part of the connection reuse key, so a later transfer asking for a different source can silently reuse an existing connection and go out from the earlier transfer's source address
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 | 8.22.0 – 8.22.0; 8.21.0 – 8.21.0; 8.20.0 – 8.20.0; 8.19.0 – 8.19.0; 8.18.0 – 8.18.0; 8.17.0 – 8.17.0; 8.16.0 – 8.16.0; 8.15.0 – 8.15.0; 8.14.1 – 8.14.1; 8.14.0 – 8.14.0; 8.13.0 – 8.13.0; 8.12.1 – 8.12.1; 8.12.0 – 8.12.0; 8.11.1 – 8.11.1; 8.11.0 – 8.11.0; 8.10.1 – 8.10.1; 8.10.0 – 8.10.0; 8.9.1 – 8.9.1; 8.9.0 – 8.9.0 | — | No fix listed | CNA |
- curl Vendorcurl Affected 8.22.0 – 8.22.0; 8.21.0 – 8.21.0; 8.20.0 – 8.20.0; 8.19.0 – 8.19.0; 8.18.0 – 8.18.0; 8.17.0 – 8.17.0; 8.16.0 – 8.16.0; 8.15.0 – 8.15.0; 8.14.1 – 8.14.1; 8.14.0 – 8.14.0; 8.13.0 – 8.13.0; 8.12.1 – 8.12.1; 8.12.0 – 8.12.0; 8.11.1 – 8.11.1; 8.11.0 – 8.11.0; 8.10.1 – 8.10.1; 8.10.0 – 8.10.0; 8.9.1 – 8.9.1; 8.9.0 – 8.9.0 Fixed in — No fix listed CNA
Remediation
Red Hat Hardened Images is fixed by RHSA-2026:82895. The sources list no fixed version for curl. Red Hat lists no available plan for Red Hat Enterprise Linux 10, Red Hat JBoss Core Services and Red Hat Satellite 6.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Red Hat 1 advisory
- RHSA-2026:82895 Released 2026-10-14 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images curl-8.23.0-0.1.hum1@aarch64, curl-8.23.0-0.1.hum1@s390x, curl-8.23.0-0.1.hum1@src +10
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat JBoss Core Services | Affected | No fix yet: Fix deferred |
| Red Hat Satellite 6 | Affected | No fix yet: Fix deferred |
| Red Hat Hardened Images | Fixed | RHSA-2026:82895 |
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat Hardened Images
- Red Hat Satellite 6
Timeline
- 2026-10-21 Threatist record created from CVE-2026-107929
- 2026-10-21 Alias added: GHSA-9644-8jhv-gxgm
- 2026-10-23 Affected versions changed · Red Hat
- 2026-10-30 CVSS score added · CISA ADP
- 2026-10-30 Weakness changed · CISA ADP
- 2026-10-30 CISA SSVC decision points changed
- 2026-10-30 Priority changed: LOW → HIGH
- 2026-10-31 EPSS moved to the 50th–90th percentile
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-2026-107929 · CVE Program
- CVE-2026-107929 · NVD
- FIRST EPSS
- GHSA-9644-8jhv-gxgm · GitHub Advisory Database · CC BY 4.0
- CVE-2026-107929 · 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