High
Libssh: invalid return code for chacha20 poly1305 with openssl backend
Type: advisorySources: OSV
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2025-5987
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 02:24 UTC · Revision 1
Source evidence
Libssh: invalid return code for chacha20 poly1305 with openssl backend
core-osv · Original sourcePublished 7 Jul 2025, 14:24 UTC
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.
osv:CVE-2025-5987
Complete source record
{
"id": "c7b6d9136d872e7ce9962c0cb1ddd39da240eebb5a411edb8bf3d61c6a0b5b23",
"url": "https://osv.dev/vulnerability/CVE-2025-5987",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Libssh: invalid return code for chacha20 poly1305 with openssl backend",
"summary": "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.",
"evidence": "osv:CVE-2025-5987",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2025-5987",
"aliases": [
"CVE-2025-5987"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://gitlab.com/libssh/libssh-mirror",
"type": "GIT",
"events": [
{
"introduced": "7f6b3fab4e8d4b97e73d5ca60ddc5a3d0f5880d2"
},
{
"fixed": "dff6c0821ed54f6fbf5b755af43f54cbb723b1b1"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0.10.0"
},
{
"fixed": "0.11.2"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-5987.json"
}
}
],
"modified": "2026-10-28T02:30:32.381511090Z",
"provider": "osv",
"references": [
"https://access.redhat.com/downloads/content/package-browser/",
"https://www.libssh.org/",
"https://access.redhat.com/errata/RHSA-2025:23483",
"https://access.redhat.com/errata/RHSA-2025:23484",
"https://access.redhat.com/errata/RHSA-2026:0427",
"https://access.redhat.com/errata/RHSA-2026:0428",
"https://access.redhat.com/errata/RHSA-2026:0430",
"https://access.redhat.com/errata/RHSA-2026:0431",
"https://access.redhat.com/errata/RHSA-2026:0702",
"https://access.redhat.com/errata/RHSA-2026:0978",
"https://access.redhat.com/errata/RHSA-2026:0980",
"https://access.redhat.com/errata/RHSA-2026:0985",
"https://access.redhat.com/errata/RHSA-2026:0996",
"https://access.redhat.com/errata/RHSA-2026:1539",
"https://access.redhat.com/errata/RHSA-2026:1541",
"https://access.redhat.com/errata/RHSA-2026:3415",
"https://access.redhat.com/security/cve/CVE-2025-5987",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/5xxx/CVE-2025-5987.json",
"https://nvd.nist.gov/vuln/detail/CVE-2025-5987",
"https://www.libssh.org/security/advisories/CVE-2025-5987.txt",
"https://bugzilla.redhat.com/show_bug.cgi?id=2376219"
],
"provider_metadata": {
"cwe_ids": [
"CWE-393"
],
"cna_assigner": "redhat",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"fixed": "0:0.11.1-5.el10_1"
},
{
"fixed": "0:0.11.1-4.el10_0.1"
},
{
"fixed": "0:0.10.4-17.el9_7"
},
{
"fixed": "0:0.10.4-17.el9_7"
},
{
"fixed": "0:0.10.4-9.el9_2.2"
},
{
"fixed": "0:0.10.4-13.el9_4.2"
},
{
"fixed": "0:0.10.4-15.el9_6.1"
},
{
"fixed": "413.92.202602240113-0"
},
{
"fixed": "414.92.202601191325-0"
},
{
"fixed": "415.92.202601271320-0"
},
{
"fixed": "416.94.202601160124-0"
},
{
"fixed": "417.94.202601120213-0"
},
{
"fixed": "418.94.202601202224-0"
},
{
"fixed": "4.19.9.6.202601260820-0"
},
{
"fixed": "4.20.9.6.202601211057-0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "InverseAffectedRanges"
}
]
},
{
"extracted_events": [
{
"range": [
{
"introduced": "0.10.0"
},
{
"fixed": "0.11.2"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/5xxx/CVE-2025-5987.json"
}
},
"related_cves": [
{
"value": "CVE-2025-5987",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 499639,
"published_at": "2025-07-07T14:24:12.576+00:00"
}