CVE-2026-92388
FTP wildcard write callback mixup
Published Oct 20, 2026
CVSS 3.1 · 9.1 Critical
EPSS < 1%
KEV · Not listed
Description
When an FTP wildcard `LIST` operation fails, libcurl omits the restoration
path meant for successful listings, leaving the write callback set to the
internal listing parser and the write callback data pointing directly to the
easy handle. Subsequent reuse of this handle triggers an immediate crash, and
cloning it via `curl_easy_duphandle()` copies this corrupted state into the
duplicate. If the original handle is subsequently freed, executing a transfer
on the cloned handle causes a heap use-after-free read against the dangling
handle reference; alternatively, reusing the original or cloned handle while
changing only `CURLOPT_WRITEDATA` (and omitting `CURLOPT_WRITEFUNCTION`)
results in type confusion, forcing the internal parser to interpret incoming
server response bytes into memory at the application-supplied write data
pointer.
path meant for successful listings, leaving the write callback set to the
internal listing parser and the write callback data pointing directly to the
easy handle. Subsequent reuse of this handle triggers an immediate crash, and
cloning it via `curl_easy_duphandle()` copies this corrupted state into the
duplicate. If the original handle is subsequently freed, executing a transfer
on the cloned handle causes a heap use-after-free read against the dangling
handle reference; alternatively, reusing the original or cloned handle while
changing only `CURLOPT_WRITEDATA` (and omitting `CURLOPT_WRITEFUNCTION`)
results in type confusion, forcing the internal parser to interpret incoming
server response bytes into memory at the application-supplied write data
pointer.
Affected Products
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CVE record
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NVD configurations
No data
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Red Hat packages
No data
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OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
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| curl | curl | unaffected |
|
No data.
No data.
| Vendor | Product | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Curl | Curl |
|
Remediation
Tracking
Advisories
| Source | ID | Title |
|---|---|---|
 Ubuntu USN |
USN-8927-1 | curl vulnerabilities |
| Ubuntu USN |
USN-8932-1 | curl vulnerabilities |
| Ubuntu USN |
USN-8927-2 | curl vulnerabilities |
Metrics
No CVSS v4.0
Attack Vector Network
Attack Complexity Low
Privileges Required None
Scope Unchanged
Confidentiality Impact None
Integrity Impact High
Availability Impact High
User Interaction None
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.699% probability within 30 days)
Exploitation poc
Automatable yes
Technical Impact partial
References
History
Oct 30, 2026 1:30 PM
Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
cvssV3_1
|
ssvc
|
Oct 20, 2026 8:30 PM
Description updated. Title updated. Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A flaw was found in curl. A remote malicious server can cause a Denial of Service (DoS) or memory corruption in applications that enable File Transfer Protocol (FTP) wildcard matching. When a wildcard listing operation fails, curl does not properly reset its internal callback handlers before the connection handle is reused or duplicated. An application that subsequently reuses or clones this corrupted handle may experience an immediate application crash or unsafe memory access. | When an FTP wildcard `LIST` operation fails, libcurl omits the restoration path meant for successful listings, leaving the write callback set to the internal listing parser and the write callback data pointing directly to the easy handle. Subsequent reuse of this handle triggers an immediate crash, and cloning it via `curl_easy_duphandle()` copies this corrupted state into the duplicate. If the original handle is subsequently freed, executing a transfer on the cloned handle causes a heap use-after-free read against the dangling handle reference; alternatively, reusing the original or cloned handle while changing only `CURLOPT_WRITEDATA` (and omitting `CURLOPT_WRITEFUNCTION`) results in type confusion, forcing the internal parser to interpret incoming server response bytes into memory at the application-supplied write data pointer. |
| Title | curl: curl: FTP wildcard write callback mixup | FTP wildcard write callback mixup |
| References |
|
Oct 18, 2026 5:00 PM
First appearance in the feed. Affected vendors updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Curl
Curl curl |
|
| Vendors & Products |
Curl
Curl curl |
Oct 15, 2026 1:30 PM
Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A flaw was found in curl. A remote malicious server can cause a Denial of Service (DoS) or memory corruption in applications that enable File Transfer Protocol (FTP) wildcard matching. When a wildcard listing operation fails, curl does not properly reset its internal callback handlers before the connection handle is reused or duplicated. An application that subsequently reuses or clones this corrupted handle may experience an immediate application crash or unsafe memory access. | |
| Title | curl: curl: FTP wildcard write callback mixup | |
| Weaknesses | CWE-416 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Weaknesses