Red Hat Security Advisory: curl security update
The curl packages provide the libcurl library and the curl utility for downloading files from servers using various protocols, including HTTP, FTP, and LDAP. Security Fix(es): * curl: libcurl: Improper certificate validation due to cached TLS settings reuse (CVE-2025-14819) * curl: curl: Authentication bypass due to incorrect connection reuse with Negotiate authentication (CVE-2026-1965) * curl: curl: Unauthorized access due to improper HTTP proxy connection reuse (CVE-2026-3784) * curl: curl: Information disclosure via OAuth2 bearer token leakage during HTTP(S) redirect (CVE-2026-3783) * curl: curl: Man-in-the-middle attack via SSH host key bypass (CVE-2026-9547) * libcurl: libcurl: Security feature bypass due to improper mTLS connection reuse (CVE-2026-8932) * curl: curl: Information disclosure via incorrect .netrc password lookup (CVE-2026-8926) * curl: curl: Insecure connection establishment due to TLS configuration mismatch (CVE-2026-8286) * curl: libcurl: Unauthorized connection reuse due to a logical error (CVE-2026-8458) * curl: curl: Cookie injection via malicious HTTP server using super cookies (CVE-2026-8924) * curl: curl: Information disclosure via incorrect Digest authentication header reuse (CVE-2026-11856) * curl: curl: SSH host verification bypass when using schemeless URLs with SFTP/SCP (CVE-2026-12064) * curl: Information disclosure due to uncleared proxy authentication state (CVE-2026-8927) * libcurl: libcurl: Information disclosure due to failure to clear proxy authentication credentials (CVE-2026-9079) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
AI Analysis
Technical Summary
CVE-2025-14819 describes a flaw in libcurl where TLS-related transfers using reused easy or multi handles and altering the CURLSSLOPT_NO_PARTIALCHAIN option may inadvertently reuse a cached CA store with reversed partial chain validation. This behavior contradicts user expectations and can cause libcurl to accept a trust chain that would normally be rejected, potentially weakening TLS certificate validation. The vulnerability has been assigned a CVSS 3.1 base score of 5.3 (AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N). Red Hat has issued an important security advisory with a patch addressing this issue in their curl packages for Red Hat Enterprise Linux 10 and related variants.
Potential Impact
The vulnerability can cause libcurl to improperly validate TLS certificate chains by reusing cached CA stores with reversed partial chain options, leading to acceptance of trust chains that should be rejected. This impacts the confidentiality of TLS connections by potentially allowing acceptance of untrusted certificates. There is no indication of integrity or availability impact. No known exploits in the wild have been reported.
Mitigation Recommendations
A patch is available and should be applied to affected libcurl versions. Red Hat has released updated curl packages for Red Hat Enterprise Linux 10 to address this vulnerability. Users should follow vendor guidance to update to the fixed versions. No additional mitigation steps are required beyond applying the official fix.
Red Hat Security Advisory: curl security update
Description
The curl packages provide the libcurl library and the curl utility for downloading files from servers using various protocols, including HTTP, FTP, and LDAP. Security Fix(es): * curl: libcurl: Improper certificate validation due to cached TLS settings reuse (CVE-2025-14819) * curl: curl: Authentication bypass due to incorrect connection reuse with Negotiate authentication (CVE-2026-1965) * curl: curl: Unauthorized access due to improper HTTP proxy connection reuse (CVE-2026-3784) * curl: curl: Information disclosure via OAuth2 bearer token leakage during HTTP(S) redirect (CVE-2026-3783) * curl: curl: Man-in-the-middle attack via SSH host key bypass (CVE-2026-9547) * libcurl: libcurl: Security feature bypass due to improper mTLS connection reuse (CVE-2026-8932) * curl: curl: Information disclosure via incorrect .netrc password lookup (CVE-2026-8926) * curl: curl: Insecure connection establishment due to TLS configuration mismatch (CVE-2026-8286) * curl: libcurl: Unauthorized connection reuse due to a logical error (CVE-2026-8458) * curl: curl: Cookie injection via malicious HTTP server using super cookies (CVE-2026-8924) * curl: curl: Information disclosure via incorrect Digest authentication header reuse (CVE-2026-11856) * curl: curl: SSH host verification bypass when using schemeless URLs with SFTP/SCP (CVE-2026-12064) * curl: Information disclosure due to uncleared proxy authentication state (CVE-2026-8927) * libcurl: libcurl: Information disclosure due to failure to clear proxy authentication credentials (CVE-2026-9079) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Affected software
pkg:deb/ubuntu/curl?arch=source&distro=noblepkg:deb/ubuntu/curl?arch=source&distro=questingRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2025-14819 describes a flaw in libcurl where TLS-related transfers using reused easy or multi handles and altering the CURLSSLOPT_NO_PARTIALCHAIN option may inadvertently reuse a cached CA store with reversed partial chain validation. This behavior contradicts user expectations and can cause libcurl to accept a trust chain that would normally be rejected, potentially weakening TLS certificate validation. The vulnerability has been assigned a CVSS 3.1 base score of 5.3 (AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N). Red Hat has issued an important security advisory with a patch addressing this issue in their curl packages for Red Hat Enterprise Linux 10 and related variants.
Potential Impact
The vulnerability can cause libcurl to improperly validate TLS certificate chains by reusing cached CA stores with reversed partial chain options, leading to acceptance of trust chains that should be rejected. This impacts the confidentiality of TLS connections by potentially allowing acceptance of untrusted certificates. There is no indication of integrity or availability impact. No known exploits in the wild have been reported.
Mitigation Recommendations
A patch is available and should be applied to affected libcurl versions. Red Hat has released updated curl packages for Red Hat Enterprise Linux 10 to address this vulnerability. Users should follow vendor guidance to update to the fixed versions. No additional mitigation steps are required beyond applying the official fix.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:55450
- Cve Count
- 7
- Additional Cves
- ["CVE-2026-1965","CVE-2026-3783","CVE-2026-3784","CVE-2026-8286","CVE-2026-9547","CVE-2026-12064"]
Threat ID: 6a83336dbf8831d5392a7e4f
Added to database: 08/17/2026, 16:14:37 UTC
Last enriched: 09/24/2026, 08:28:51 UTC
Last updated: 10/03/2026, 02:46:00 UTC
Views: 127
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