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Findings

Vulnerability · USN-8932-1

curl vulnerabilities

Published Oct 14, 2026 · corrected/updated Oct 17, 2026 · evidence confidence medium

Stanislav Fort discovered that curl did not properly clear AWS SigV4 authentication state when CURLOPT_AWS_SIGV4 was set to NULL. An attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-86409) Stanislav Fort discovered that an HTTP proxy could trick libcurl into sending credentials to the proxy itself by responding to a CONNECT request with an unexpected authentication challenge. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-86414) Stanislav Fort discovered that curl did not correctly handle HSTS entries when an includeSubDomains parent entry was imported before a longer-lived child entry. An attacker could possibly use this issue to cause curl to use unencrypted HTTP connections. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-87862) Stanislav Fort discovered that curl did not properly handle HSTS max-age values that exceeded calendar time structure bounds. An attacker could possibly use this issue to cause a denial of service or data loss. This issue only affected Ubuntu 24.04 LTS. (CVE-2026-87863) Stanislav Fort discovered that curl did not properly handle IMAP APPEND commands when CURLOPT_CRLF was enabled, allowing overflow bytes to be interpreted as pipelined commands. An authenticated attacker could possibly use this issue to inject arbitrary IMAP commands. (CVE-2026-87864) Joshua Rogers discovered that libcurl had a use-after-free vulnerability in the FTP wildcard matching code. An attacker could possibly use this issue to cause curl to crash, resulting in a denial of service, or execute arbitrary code. (CVE-2026-92388) Joshua Rogers discovered that libcurl's TFTP state machine did not properly validate transfer directions, allowing a malicious server to force the client into transmit mode. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-92389) Joshua Rogers discovere

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

USN-8932-1 is a unknown public vulnerability record for this product. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether this product is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: curl (0 → 7.81.0-1ubuntu1.30); curl (0 → 8.5.0-2ubuntu10.16); curl (0 → 7.35.0-1ubuntu2.20+esm24); curl (0 → 7.47.0-1ubuntu2.19+esm21). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: no CVSS/EPSS yet. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: osv. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Technology hubs

Ubuntu

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 14, 2026 · OpenSSF OSV / OSV Scanner

    Detected

    Stanislav Fort discovered that curl did not properly clear AWS SigV4 authentication state when CURLOPT_AWS_SIGV4 was set to NULL. An attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-86409) Stanislav Fort discovered that an HTTP proxy could trick libcurl into sending credentials to the proxy itself by r

  2. Oct 17, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    curl fixed in 7.35.0-1ubuntu2.20+esm24; curl fixed in 7.47.0-1ubuntu2.19+esm21; curl fixed in 7.58.0-2ubuntu3.24+esm15; curl fixed in 7.68.0-1ubuntu2.25+esm10

  3. Oct 17, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    curl fixed in 7.35.0-1ubuntu2.20+esm24

  4. Oct 17, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    curl fixed in 7.47.0-1ubuntu2.19+esm21

  5. Oct 17, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    curl fixed in 7.58.0-2ubuntu3.24+esm15

  6. Oct 17, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    curl fixed in 7.68.0-1ubuntu2.25+esm10

  7. Oct 17, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    curl fixed in 7.81.0-1ubuntu1.30

  8. Oct 17, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    curl fixed in 8.5.0-2ubuntu10.16

  9. Oct 17, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    Stanislav Fort discovered that curl did not properly clear AWS SigV4 authentication state when CURLOPT_AWS_SIGV4 was set to NULL. An attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-86409) Stanislav Fort discovered that an HTTP proxy could trick libcurl into sending credentials to the proxy itself by r

  10. Oct 17, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    Stanislav Fort discovered that curl did not properly clear AWS SigV4 authentication state when CURLOPT_AWS_SIGV4 was set to NULL. An attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-86409) Stanislav Fort discovered that an HTTP proxy could trick libcurl into sending credentials to the proxy itself by r

Affected

  • Ubuntu:22.04:LTS curl0 → 7.81.0-1ubuntu1.30
  • Ubuntu:24.04:LTS curl0 → 8.5.0-2ubuntu10.16
  • Ubuntu:Pro:14.04:LTS curl0 → 7.35.0-1ubuntu2.20+esm24
  • Ubuntu:Pro:16.04:LTS curl0 → 7.47.0-1ubuntu2.19+esm21
  • Ubuntu:Pro:18.04:LTS curl0 → 7.58.0-2ubuntu3.24+esm15
  • Ubuntu:Pro:20.04:LTS curl0 → 7.68.0-1ubuntu2.25+esm10

Sources

References