Uncontrolled recursion in curl_mime_free causes stack overflow
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 fixed, 6 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-674.
Summary
curl releases 7.56.0 through 8.22.0 are affected. Uncontrolled recursion (CWE-674) in curl_mime_free lets a deeply nested multipart MIME structure built through the public API overflow the stack during cleanup and crash the host process. An unauthenticated remote attacker can trigger the crash without user interaction.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
Description from the CNA
A deeply nested multipart MIME structure constructed via the public API causes a stack overflow in libcurl during normal cleanup operations. An excessive recursion depth within `curl_mime_free` leads to unbounded stack frame allocation during structure traversal, ultimately crashing the host process.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
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; 8.8.0 – 8.8.0; 8.7.1 – 8.7.1; 8.7.0 – 8.7.0; 8.6.0 – 8.6.0; 8.5.0 – 8.5.0; 8.4.0 – 8.4.0; 8.3.0 – 8.3.0; 8.2.1 – 8.2.1; 8.2.0 – 8.2.0; 8.1.2 – 8.1.2; 8.1.1 – 8.1.1; 8.1.0 – 8.1.0; 8.0.1 – 8.0.1; 8.0.0 – 8.0.0; 7.88.1 – 7.88.1; 7.88.0 – 7.88.0; 7.87.0 – 7.87.0; 7.86.0 – 7.86.0; 7.85.0 – 7.85.0; 7.84.0 – 7.84.0; 7.83.1 – 7.83.1; 7.83.0 – 7.83.0; 7.82.0 – 7.82.0; 7.81.0 – 7.81.0; 7.80.0 – 7.80.0; 7.79.1 – 7.79.1; 7.79.0 – 7.79.0; 7.78.0 – 7.78.0; 7.77.0 – 7.77.0; 7.76.1 – 7.76.1; 7.76.0 – 7.76.0; 7.75.0 – 7.75.0; 7.74.0 – 7.74.0; 7.73.0 – 7.73.0; 7.72.0 – 7.72.0; 7.71.1 – 7.71.1; 7.71.0 – 7.71.0; 7.70.0 – 7.70.0; 7.69.1 – 7.69.1; 7.69.0 – 7.69.0; 7.68.0 – 7.68.0; 7.67.0 – 7.67.0; 7.66.0 – 7.66.0; 7.65.3 – 7.65.3; 7.65.2 – 7.65.2; 7.65.1 – 7.65.1; 7.65.0 – 7.65.0; 7.64.1 – 7.64.1; 7.64.0 – 7.64.0; 7.63.0 – 7.63.0; 7.62.0 – 7.62.0; 7.61.1 – 7.61.1; 7.61.0 – 7.61.0; 7.60.0 – 7.60.0; 7.59.0 – 7.59.0; 7.58.0 – 7.58.0; 7.57.0 – 7.57.0; 7.56.1 – 7.56.1; 7.56.0 – 7.56.0 | — | 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; 8.8.0 – 8.8.0; 8.7.1 – 8.7.1; 8.7.0 – 8.7.0; 8.6.0 – 8.6.0; 8.5.0 – 8.5.0; 8.4.0 – 8.4.0; 8.3.0 – 8.3.0; 8.2.1 – 8.2.1; 8.2.0 – 8.2.0; 8.1.2 – 8.1.2; 8.1.1 – 8.1.1; 8.1.0 – 8.1.0; 8.0.1 – 8.0.1; 8.0.0 – 8.0.0; 7.88.1 – 7.88.1; 7.88.0 – 7.88.0; 7.87.0 – 7.87.0; 7.86.0 – 7.86.0; 7.85.0 – 7.85.0; 7.84.0 – 7.84.0; 7.83.1 – 7.83.1; 7.83.0 – 7.83.0; 7.82.0 – 7.82.0; 7.81.0 – 7.81.0; 7.80.0 – 7.80.0; 7.79.1 – 7.79.1; 7.79.0 – 7.79.0; 7.78.0 – 7.78.0; 7.77.0 – 7.77.0; 7.76.1 – 7.76.1; 7.76.0 – 7.76.0; 7.75.0 – 7.75.0; 7.74.0 – 7.74.0; 7.73.0 – 7.73.0; 7.72.0 – 7.72.0; 7.71.1 – 7.71.1; 7.71.0 – 7.71.0; 7.70.0 – 7.70.0; 7.69.1 – 7.69.1; 7.69.0 – 7.69.0; 7.68.0 – 7.68.0; 7.67.0 – 7.67.0; 7.66.0 – 7.66.0; 7.65.3 – 7.65.3; 7.65.2 – 7.65.2; 7.65.1 – 7.65.1; 7.65.0 – 7.65.0; 7.64.1 – 7.64.1; 7.64.0 – 7.64.0; 7.63.0 – 7.63.0; 7.62.0 – 7.62.0; 7.61.1 – 7.61.1; 7.61.0 – 7.61.0; 7.60.0 – 7.60.0; 7.59.0 – 7.59.0; 7.58.0 – 7.58.0; 7.57.0 – 7.57.0; 7.56.1 – 7.56.1; 7.56.0 – 7.56.0 Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for curl. Red Hat fixes Red Hat Hardened Images in RHSA-2026:82895, and lists no fix available for Red Hat Enterprise Linux 8, 9 and 10, Red Hat JBoss Core Services and Red Hat Satellite 6.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
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 Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat JBoss Core Services | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | — |
| 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 9
- Red Hat Hardened Images
- Red Hat OpenShift AI (RHOAI)
- Red Hat Satellite 6
Timeline
- 2026-10-21 Threatist record created from CVE-2026-92391
- 2026-10-21 Alias added: GHSA-gm44-4wrm-hqf2
- 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
- 2026-11-07 Affected versions changed · Red Hat
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-2026-92391 · CVE Program
- CVE-2026-92391 · NVD
- FIRST EPSS
- GHSA-gm44-4wrm-hqf2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-92391 · 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