CVE-2025-5987: A flaw was found in libssh when using the ChaCha20 cipher with the OpenSSL library. If an attacker manages to exhaust the heap space, this error is not…

PriorityP350high8.1CVSS 3.1

AVNACHPRNUINSUCHIHAH

EPSS

1.44%

70.2th percentile

A flaw was found in libssh when using the ChaCha20 cipher with the OpenSSL library. If an attacker manages to exhaust the heap space, this error is not detected and may lead to libssh using a partially initialized cipher context. This occurs because the OpenSSL error code returned aliases with the SSH_OK code, resulting in libssh not properly detecting the error returned by the OpenSSL library. This issue can lead to undefined behavior, including compromised data confidentiality and integrity or crashes.

Affected

11 ranges

Vendor	Product	Version range	Fixed in
debian	libssh	< libssh 0.10.6-0+deb12u2 (bookworm)	libssh 0.10.6-0+deb12u2 (bookworm)
libssh	libssh	>= 0 < 0.10.6-0+deb12u2	0.10.6-0+deb12u2
libssh	libssh	>= 0 < 0.11.2-1	0.11.2-1
libssh	libssh	>= 0 < 0.11.2-1	0.11.2-1
libssh	libssh	>= 0 < 0.9.6-2ubuntu0.22.04.4	0.9.6-2ubuntu0.22.04.4
libssh	libssh	>= 0 < 0.10.6-2ubuntu0.1	0.10.6-2ubuntu0.1
libssh	libssh	>= 0.10.0 < 0.11.2	0.11.2
msrc	azl3_libssh_0.10.6-1_on_azure_linux_3.0	—	—
msrc	azl3_libssh_0.10.6-2_on_azure_linux_3.0	—	—
msrc	cbl2_libssh_0.10.6-1_on_cbl_mariner_2.0	—	—
msrc	cbl2_libssh_0.10.6-2_on_cbl_mariner_2.0	—	—

CVSS provenance

nvdv3.18.1HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

osv8.1HIGH

vendor_debian8.1HIGH

vendor_oracle8.1HIGH

vendor_redhat8.1HIGH

vendor_msrc5.0MEDIUM

vendor_ubuntu4.5MEDIUM

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