VulnSocial

CVE-2026-66034(libssh2 / libssh2)

LOWCVSS 7.7 · HIGH

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

libssh2 through 1.11.1, fixed in commit a13bb6c, contains a missing bounds check vulnerability that allows a malicious SSH server to trigger an arbitrary-length heap out-of-bounds read and a free of an uninitialized pointer via the publickey subsystem. In libssh2_publickey_list_fetch(), the version 1 response parser reads a server-controlled comment_len value and advances the parse pointer without verifying sufficient bytes remain in the buffer, causing the out-of-bounds read to leak heap pointers from adjacent allocations defeating ASLR, followed by heap allocator state corruption when the error cleanup path frees an uninitialized pointer from a non-zeroed realloc() region.

libssh2 CVEsBack to dashboard
0.0/ 10 priority

Sources & remediation

Patch / fix
Weakness type (CWE)
CWE-125CWE-908

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • libssh2

Affected systems

Vendors
libssh2
Products
libssh2

Deep dive

Full discourse2 posts
  • iototsecnews@iototsecnews
    Patch

    libssh2 の脆弱性 CVE-2026-66032／66033／66034／66035 が FIX：悪意の SSH サーバによるクライアント破壊 https://iototsecnews.jp/2026/07/28/libssh2-vulnerabilities-allow-a-malicious-ssh-server-to-corrupt-client-memory/ libssh2 の脆弱性 CVE-2026-66032／CVE-2026-66033／CVE-2026-66034／CVE-2026-66035 は、接続時のデータ検証やメモリ管理の不備に起因するものです。悪意の送信元との通信により内部の処理が乱され、プログラムの停止や意図しない動作などが引き起こされる恐れがあります。システムを安全に利用するためにも、対策が施された修正版ライブラリへの更新を速やかに実施してください。組み込み型のプログラムを利用している場合には、個別でのアップデート対応が必要になる点にも注意が必要です。 #CVE202666032 #CVE202666033 #CVE202666034 #CVE202666035 #libssh2 #Vulnerability

    Post summary

    The article announces that libssh2 vulnerabilities (CVE‑2026‑66032‑66035) have been fixed, explains the cause and impact, and urges users to update to the patched library.

    02000159
    506 followersView on X
  • Rıdvan Yağlı@ridvanyagli
    Disclosure

    🔴 libssh2'de keşfedilen dört kritik güvenlik açığı (CVE-2026-66032, CVE-2026-66033, CVE-2026-66034 ve CVE-2026-66035), kötü niyetli bir SSH/SFTP sunucusunun istemci uygulamalarında bellek bozulmasına, uygulamanın çökmesine ve bazı senaryolarda potansiyel uzaktan kod çalıştırmaya neden olabilmesine yol açıyor. Etkilenen sürümler: libssh2 1.11.1 ve öncesi. Kullanıcıların ve sistem yöneticilerinin, libssh2'yi veya bu kütüphaneyi kullanan uygulamaları güncel sürüme yükseltmeleri önerilir.

    Post summary

    Four critical CVEs were discovered in libssh2 that can cause memory corruption, crashes, and potentially remote code execution; users are advised to upgrade to a newer version.

    0000084
    1.3K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Applibssh2libssh2---

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