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CVE

CVE-2026-55200

libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c
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CVE

CVE-2026-55200

libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread() that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve remote code execution.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.2
-
4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55200.json, https://nvd.nist.gov/vuln/detail/CVE-2026-55200, https://www.vulncheck.com/advisories/libssh2-out-of-bounds-write-via-unchecked-packet-length-in-transport-c, https://github.com/libssh2/libssh2/pull/2052, https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8, https://github.com/libssh2/libssh2, https://web.archive.org/web/20260623211210/https://github.com/bikini/exploitarium/tree/main/libssh2-cve-2026-55200-poc

Severity

0

CVSS Score
0
10

Basic Information

Base CVSS
0
EPSS Probability
0.02027%
EPSS Percentile
0.79512%
Introduced Version
0
Fix Available
97acf3dfda80c91c3a8c9f2372546301d4a1a7a8,1.11.1-1+deb13u1,1.11.1-r3,1.11.1-r2,1.11.1-r6

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