HighFix available
weechat — security advisory
WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 0.3.1 through 4.9.0, the WeeChat relay authentication uses non-constant-time string comparison functions (weechat_strcasecmp and strcmp) to verify password hashes and plaintext passwords. An attacker can exploit timing differences to extract the server-computed hash character by character, then authenticate using the correct hash without knowing the password. Version 4.9.1 fixes the issue.
- Products
- weechat
- Affected versions
- 3.8-1, 4.0.1-1, 4.0.2-1, 4.0.5-1, 4.1.1-1, 4.10.0-1, 4.3.1-1, 4.4.2-1, 4.4.3-1, 4.4.3-1~bpo12+1, 4.5.1-1, 4.6.1-1, 4.6.3-1, 4.6.3-1~bpo12+1, 4.7.2-1, 4.8.1-1, 4.9.0-1, 4.9.3-1, 4.9.4-1, 4.9.5-1
- Fixed versions
- 4.9.3-1
- CVEs
- CVE-2026-53525
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 16:45 UTC · Revision 1
Source evidence
WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 0.3.1 through 4.9.0, the WeeChat relay authentication uses non-constant-time string comparison functions (weechat_strcasecmp and strcmp) to verify password hashes and plaintext passwords. An attacker can exploit timing differences to extract the server-computed hash character by character, then authenticate using the correct hash without knowing the password. Version 4.9.1 fixes the issue.
osv:DEBIAN-CVE-2026-53525
weechat
Fixed versions: Not specified
weechat
Fixed versions: Not specified
weechat
Fixed versions: 4.9.3-1
Complete source record
{
"id": "4cc46385c00b9dad9d2bb3ce14844df8a9e47533fff5e999e7bf1c562abde76c",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-53525",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-53525",
"summary": "WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 0.3.1 through 4.9.0, the WeeChat relay authentication uses non-constant-time string comparison functions (weechat_strcasecmp and strcmp) to verify password hashes and plaintext passwords. An attacker can exploit timing differences to extract the server-computed hash character by character, then authenticate using the correct hash without knowing the password. Version 4.9.1 fixes the issue.",
"evidence": "osv:DEBIAN-CVE-2026-53525",
"products": [
{
"name": {
"value": "weechat",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.8-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.0.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.0.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.0.5-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.1.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.10.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.3.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.4.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.4.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.4.3-1~bpo12+1",
"evidence": "/affected/0/versions"
},
{
"value": "4.5.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.6.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.6.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.6.3-1~bpo12+1",
"evidence": "/affected/0/versions"
},
{
"value": "4.7.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.8.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.9.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.9.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.9.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.9.5-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "weechat",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.10.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.6.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.7.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.8.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.9.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.9.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.9.4-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.9.5-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "weechat",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.9.3-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "4.6.3-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.7.2-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.8.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.9.0-1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-53525",
"aliases": [
"DEBIAN-CVE-2026-53525"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "weechat",
"purl": "pkg:deb/debian/weechat?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"3.8-1",
"4.0.1-1",
"4.0.2-1",
"4.0.5-1",
"4.1.1-1",
"4.10.0-1",
"4.3.1-1",
"4.4.2-1",
"4.4.3-1",
"4.4.3-1~bpo12+1",
"4.5.1-1",
"4.6.1-1",
"4.6.3-1",
"4.6.3-1~bpo12+1",
"4.7.2-1",
"4.8.1-1",
"4.9.0-1",
"4.9.3-1",
"4.9.4-1",
"4.9.5-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53525.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "weechat",
"purl": "pkg:deb/debian/weechat?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"4.10.0-1",
"4.6.3-1",
"4.7.2-1",
"4.8.1-1",
"4.9.0-1",
"4.9.3-1",
"4.9.4-1",
"4.9.5-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53525.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.9.3-1"
}
]
}
],
"package": {
"name": "weechat",
"purl": "pkg:deb/debian/weechat?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"4.6.3-1",
"4.7.2-1",
"4.8.1-1",
"4.9.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53525.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-15T09:47:38.871914556Z",
"provider": "osv",
"upstream": [
"CVE-2026-53525"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-53525"
]
},
"related_cves": [
{
"value": "CVE-2026-53525",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 328132,
"published_at": "2026-08-21T23:16:26.363+00:00"
}