VulnerabilityModified

CVE-2025-5987

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.

HIGH 8.1EPSS 1.49%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.49%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1: 8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 1.49% probability · 73th percentile
CISA KEV: Not listed
Weakness: CWE-393
Affected: libssh/libssh
Source: secalert@redhat.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.