Issue summary: An application using the OpenSSL HTTP client API functions may trigger an out-of-bounds read if the 'no_proxy' environment variable is set and the host portion of the authority component of the HTTP URL is an IPv6 address.
Impact summary: An out-of-bounds read can trigger a crash which leads to Denial of Service for an application.
The OpenSSL HTTP client API functions can be used directly by applications but they are also used by the OCSP client functions and CMP (Certificate Management Protocol) client implementation in OpenSSL. However the URLs used by these implementations are unlikely to be controlled by an attacker.
In this vulnerable code the out of bounds read can only trigger a crash. Furthermore the vulnerability requires an attacker-controlled URL to be passed from an application to the OpenSSL function and the user has to have a 'no_proxy' environment variable set. For the aforementioned reasons the issue was assessed as Low severity.
The vulnerable code was introduced in the following patch releases: 3.0.16, 3.1.8, 3.2.4, 3.3.3, 3.4.0 and 3.5.0.
The FIPS modules in 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this issue, as the HTTP client implementation is outside the OpenSSL FIPS module boundary.
CVSS Details
- CVSS 3.1 Base Score: 5.9
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade openssl | Oct 2, 2025 | Sep 30, 2025 |
| Debian | — | Upgrade openssl | Oct 2, 2025 | Oct 2, 2025 |
| Freebsd | — | Upgrade openssl35Upgrade openssl32Upgrade openssl36Upgrade openssl33-quictlsUpgrade openssl34Upgrade openssl33Upgrade openssl | Dec 10, 2025 | Oct 1, 2025 |
| Http Openssl | — | Upgrade to the latest version of OpenSSL | Mar 5, 2026 | Sep 30, 2025 |
| Ibm Aix | — | Apply the fix or workaround for openssl_advisory45 | Dec 11, 2025 | Dec 10, 2025 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Sep 30, 2025 |
| Ubuntu | — | Upgrade ovmfUpgrade ovmf-ia32Upgrade qemu-efiUpgrade qemu-efi-aarch64Upgrade libssl3t64Upgrade qemu-efi-armUpgrade qemu-efi-loongarch64Upgrade qemu-efi-riscv64Upgrade openssl | Oct 1, 2025 | Sep 30, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Feb 9, 2026 | Sep 30, 2025 |
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