CVE record · CVE-2025-4877

Libssh: write beyond bounds in binary to base64 conversion functions

CVSS 4.5 MediumEPSS 0.0020 · 10th percentile

Published by the CVE Program (CNA: redhat) at 20 Aug 2025, 12:19 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
Not given	Not given Package name: libssh https://www.libssh.org	affected before 0.11.2 semver Other versions: unaffected
Red Hat	Red Hat Enterprise Linux 9 Package name: libssh https://access.redhat.com/downloads/content/package-browser/	unaffected 0:0.10.4-18.el9 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 9 Package name: libssh https://access.redhat.com/downloads/content/package-browser/	unaffected 0:0.10.4-18.el9 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 10 Package name: libssh https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: unaffected
Red Hat	Red Hat Enterprise Linux 6 Package name: libssh2 https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: unaffected
Red Hat	Red Hat Enterprise Linux 7 Package name: libssh2 https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: unaffected
Red Hat	Red Hat Enterprise Linux 8 Package name: libssh https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: unaffected
Red Hat	Red Hat OpenShift Container Platform 4 Package name: openshift/ose-rhel-coreos-8 https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: unaffected
Red Hat	Red Hat OpenShift Container Platform 4 Package name: openshift/ose-rhel-coreos-9 https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: unaffected

Identifiers: CVE-2025-4877
CNA: redhat
Weakness (CWE): CWE-787
Tags: Red Hat Enterprise Linux 9
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Red Hat OpenShift Container Platform 4
Memory corruption
Published: 20 Aug 2025
Updated: 5 Nov 2026

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
4.5	Medium	3.1	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L	CNA (redhat)

CISA KEV Not listed.
EPSS 0.0020, the 10th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

20 Aug 2025, 12:19 UTC Confirmed by the CVE List
20 Aug 2025, 13:15 UTC Confirmed by NVD

Sources

References from the CNA

access.redhat.com/errata/RHSA-2026:18683 vendor-advisoryredhat
access.redhat.com/security/cve/CVE-2025-4877 vdb-entryredhat
bugzilla.redhat.com/show_bug.cgi?id=2376193 issue-trackingredhat
git.libssh.org/projects/libssh.git/commit/?h=stable-0.11&id=6fd9cc8ce3958092a1aae11f1f2e911b2747732d
www.libssh.org/security/advisories/CVE-2025-4877.txt

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.