CVE-2026-66035 @ mufasa
Status
not_applicable
Priority
7.5
Match score
4.0
Risk
MemCorrupt
CVSS
7.5 HIGH
Reason
cpe: libssh2; pkgs: libssh2; version: in-range: alt-libssh2-1.8.0-2.el7, libssh2-1.8.0-4.el7_9.1.tuxcare.els2; risk:memory_corruption
Created
2026-08-02T19:35:07Z
Updated
2026-08-02T22:55:12Z
Closed
2026-08-02T20:43:59Z
Package interrogation (copy)
Run on the host — click to copy a command. RPM
| Package | Commands |
|---|---|
| alt-libssh2-1.8.0-2.el7 | |
| libssh2-1.8.0-4.el7_9.1.tuxcare.els2 |
Inventory lookup
Search package inventory across systems, then return here. Create a ticket on systems the matcher missed.
Suggestions: alt-libssh2 · libssh2
Same product CVEs in your queue
Other tickets that look like the same product (from match reason). Relate them here to triage this CVE as the primary.
| CVE | CVSS | KEV | Systems | Status | Matched | Already related | |
|---|---|---|---|---|---|---|---|
| CVE-2026-66032 | 8.8 | Helios, morris, mufasa | accepted_risk | libssh2 | — | ||
| CVE-2026-66033 | 7.5 | Helios, morris, mufasa | accepted_risk | libssh2 | — | ||
| CVE-2026-66034 | 7.5 | Helios, morris, mufasa | accepted_risk, not_applicable | libssh2 | → CVE-2026-66033 |
Related CVE (same fix)
This CVE is subordinated to primary CVE-2026-66033 — same product as CVE-2026-66033
Host OS / kernel
OS
CloudLinux release 7.9 (Boris Yegorov)
(7.9)
· cloudlinux
Arch
x86_64
kernel_release
uname -r → 3.10.0-962.3.2.lve1.5.89.el7.x86_64kernel_version
uname -v → #1 SMP Thu Jul 9 15:55:31 UTC 2026For Linux kernel CVEs, kernel_version (Debian packaging / build string) often decides fixed vs not; kernel_release is used for upstream NVD range compares.
Same CVE on other hosts
Open the ticket for this CVE on another system.
| System | Status | Priority | Updated | |
|---|---|---|---|---|
| morris | not_applicable | 7.5 | 2026-08-02T22:55:12Z | Open |
Description
libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packet_length smaller than the cipher's block size during Encrypt-then-MAC cipher negotiation. In the fullpacket() function in src/transport.c, the ETM path allocates a buffer of packet_length bytes but copies blocksize minus one bytes via memcpy, causing an overflow that on 32-bit glibc writes attacker-controlled bytes into an adjacent chunk's SIZE field, enabling tcache bin confusion, overlapping live objects, and function pointer overwrite during the session handshake before authentication.
Determination
Related to primary CVE-2026-66033: same product as CVE-2026-66033
Update status
Add note only
Mitigation log
2026-08-02T20:43:59Z — not_applicable
Related to primary CVE-2026-66033: same product as CVE-2026-66033
References
- https://github.com/libssh2/libssh2/commit/42e33d81577ed4b95d4b4f6f845e5ee8efe5eeb4
- https://github.com/libssh2/libssh2/pull/2198
- https://www.vulncheck.com/advisories/libssh2-heap-buffer-overflow-via-etm-cipher-negotiation
NVD: CVE-2026-66035