csirt@kutim:~/threat-intel/cve/CVE-2025-66199

Katalog CVE

CVSS 5.9 · Medium EPSS 0,45%

Kerentanan Memory Allocation with Excessive Size Value pada openssl. Skor CVSS 3.1 5.9 (Medium) menurut CISA ADP.

Deskripsi (NVD)

Issue summary: A TLS 1.3 connection using certificate compression can be forced to allocate a large buffer before decompression without checking against the configured certificate size limit. Impact summary: An attacker can cause per-connection memory allocations of up to approximately 22 MiB and extra CPU work, potentially leading to service degradation or resource exhaustion (Denial of Service). In affected configurations, the peer-supplied uncompressed certificate length from a CompressedCertificate message is used to grow a heap buffer prior to decompression. This length is not bounded by the max_cert_list setting, which otherwise constrains certificate message sizes. An attacker can exploit this to cause large per-connection allocations followed by handshake failure. No memory corruption or information disclosure occurs. This issue only affects builds where TLS 1.3 certificate compression is compiled in (i.e., not OPENSSL_NO_COMP_ALG) and at least one compression algorithm (brotli, zlib, or zstd) is available, and where the compression extension is negotiated. Both clients receiving a server CompressedCertificate and servers in mutual TLS scenarios receiving a client CompressedCertificate are affected. Servers that do not request client certificates are not vulnerable to client-initiated attacks. Users can mitigate this issue by setting SSL_OP_NO_RX_CERTIFICATE_COMPRESSION to disable receiving compressed certificates. The FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue, as the TLS implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue. OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.

Rincian

Terbit di NVD
27 Januari 2026
Terakhir diubah
17 Juni 2026
Status NVD
Analyzed
CVSS 3.1
5.9 (Medium), sumber CISA ADP
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H · uraikan di kalkulator
Jenis kelemahan (CWE)
CWE-789: Memory Allocation with Excessive Size Value
EPSS (30 hari)
0,45% peluang dieksploitasi; lebih tinggi dari 37,5% CVE lain

Produk dan versi terdampak

VendorProdukVersi terdampak
openssl openssl Versi 3.3.0 hingga sebelum 3.3.6
openssl openssl Versi 3.4.0 hingga sebelum 3.4.4
openssl openssl Versi 3.5.0 hingga sebelum 3.5.5
openssl openssl Versi 3.6.0 hingga sebelum 3.6.1

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 5 Okt 2026, 20:11 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.