Critical
389-ds-base — security advisory
A flaw was found in 389-ds-base. The server does not discard plaintext bytes already buffered from a client connection when negotiating StartTLS, allowing an on-path attacker to inject a crafted LDAP message that is processed after the TLS upgrade and whose response is delivered to the client in place of the client's own pending operation's response, due to messageID collision. This can cause a client application to treat a failed authentication (bind) attempt as successful.
- Products
- 389-ds-base
- Affected versions
- 2.3.1+dfsg1-1, 2.3.1+dfsg1-1+deb12u1, 2.3.4+dfsg1-1, 2.3.4+dfsg1-1.1, 2.4.4+dfsg1-1, 2.4.4+dfsg1-3, 2.4.5+dfsg1-1, 3.0.2+dfsg1-1, 3.1.1+dfsg1-1, 3.1.1+dfsg1-2, 3.1.1+dfsg1-3, 3.1.2+dfsg1-1, 3.1.2+dfsg1-1+deb13u1, 3.1.2+vendor1-1, 3.1.2+vendor1-2, 3.3.0-1, 3.3.0-2, 3.3.1-1, 3.3.1-3
- Fixed versions
- Not specified
- CVEs
- CVE-2026-86345
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 09:02 UTC · Revision 1
Source evidence
A flaw was found in 389-ds-base. The server does not discard plaintext bytes already buffered from a client connection when negotiating StartTLS, allowing an on-path attacker to inject a crafted LDAP message that is processed after the TLS upgrade and whose response is delivered to the client in place of the client's own pending operation's response, due to messageID collision. This can cause a client application to treat a failed authentication (bind) attempt as successful.
osv:DEBIAN-CVE-2026-86345
389-ds-base
Fixed versions: Not specified
389-ds-base
Fixed versions: Not specified
Complete source record
{
"id": "995bab1edcf0184d2c2af078385d44c838500c5424afcba888c02cfd03492bb4",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-86345",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-86345",
"summary": "A flaw was found in 389-ds-base. The server does not discard plaintext bytes already buffered from a client connection when negotiating StartTLS, allowing an on-path attacker to inject a crafted LDAP message that is processed after the TLS upgrade and whose response is delivered to the client in place of the client's own pending operation's response, due to messageID collision. This can cause a client application to treat a failed authentication (bind) attempt as successful.",
"evidence": "osv:DEBIAN-CVE-2026-86345",
"products": [
{
"name": {
"value": "389-ds-base",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.3.1+dfsg1-1",
"evidence": "/affected/0/versions"
},
{
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"evidence": "/affected/0/versions"
},
{
"value": "2.3.4+dfsg1-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.3.4+dfsg1-1.1",
"evidence": "/affected/0/versions"
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{
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{
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{
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{
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{
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{
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{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
},
{
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"evidence": "/affected/0/versions"
},
{
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"evidence": "/affected/0/versions"
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{
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{
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"evidence": "/affected/0/versions"
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{
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{
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{
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"affected_versions": [
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{
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"evidence": "/affected/1/versions"
},
{
"value": "3.1.2+vendor1-1",
"evidence": "/affected/1/versions"
},
{
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"evidence": "/affected/1/versions"
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{
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"evidence": "/affected/1/versions"
},
{
"value": "3.3.0-2",
"evidence": "/affected/1/versions"
},
{
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},
{
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}
]
}
],
"severity": "critical",
"structured": {
"id": "DEBIAN-CVE-2026-86345",
"aliases": [
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],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "389-ds-base",
"purl": "pkg:deb/debian/389-ds-base?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"2.3.1+dfsg1-1",
"2.3.1+dfsg1-1+deb12u1",
"2.3.4+dfsg1-1",
"2.3.4+dfsg1-1.1",
"2.4.4+dfsg1-1",
"2.4.4+dfsg1-3",
"2.4.5+dfsg1-1",
"3.0.2+dfsg1-1",
"3.1.1+dfsg1-1",
"3.1.1+dfsg1-2",
"3.1.1+dfsg1-3",
"3.1.2+dfsg1-1",
"3.1.2+vendor1-1",
"3.1.2+vendor1-2",
"3.3.0-1",
"3.3.0-2",
"3.3.1-1",
"3.3.1-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-86345.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
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}
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],
"package": {
"name": "389-ds-base",
"purl": "pkg:deb/debian/389-ds-base?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"3.1.2+dfsg1-1",
"3.1.2+dfsg1-1+deb13u1",
"3.1.2+vendor1-1",
"3.1.2+vendor1-2",
"3.3.0-1",
"3.3.0-2",
"3.3.1-1",
"3.3.1-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-86345.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-08T09:47:27.099481789Z",
"provider": "osv",
"upstream": [
"CVE-2026-86345"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-86345"
]
},
"related_cves": [
{
"value": "CVE-2026-86345",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 98865,
"published_at": "2026-10-02T00:17:04.18+00:00"
}