High
WeeChat has Non-Constant-Time Password Hash Comparison in Relay Authentication
Type: advisorySources: OSV
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
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-53525
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 06:08 UTC · Revision 1
Source evidence
WeeChat has Non-Constant-Time Password Hash Comparison in Relay Authentication
core-osv · Original sourcePublished 21 Aug 2026, 22:19 UTC
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:CVE-2026-53525
Complete source record
{
"id": "8556ff28d4398327f7da618cc623378e0c901aaac2f93270e67c28c3652123ed",
"url": "https://osv.dev/vulnerability/CVE-2026-53525",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "WeeChat has Non-Constant-Time Password Hash Comparison in Relay Authentication",
"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:CVE-2026-53525",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-53525",
"aliases": [
"CVE-2026-53525",
"GHSA-vhv8-g2r9-cwcc"
],
"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": [
{
"repo": "https://github.com/weechat/weechat",
"type": "GIT",
"events": [
{
"introduced": "0b89084ea4dc5cfe353541a41059d62b62d8dc84"
},
{
"fixed": "2148829ebe47d8ac2377ef234162bf6b64c5b466"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0.3.4"
},
{
"fixed": "4.9.1"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"introduced": "0.3.1"
},
{
"last_affected": "4.9.0"
}
],
"source": "DESCRIPTION"
}
]
}
}
],
"versions": [
"v4.9.0",
"v4.8.0",
"v4.7.0",
"v4.6.0",
"v4.5.0",
"v3.8",
"v4.4.0",
"v4.3.0",
"v4.2.0",
"v4.1.0",
"v4.0.0",
"v4.0.0-rc1",
"v3.8-rc1",
"v3.7",
"v3.6",
"v3.6-rc1",
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"v3.5-rc1",
"v3.4",
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"v3.3",
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"v2.3",
"v3.2",
"v3.2-rc1",
"v3.1",
"v3.1-rc1",
"v3.0",
"v3.0-rc1",
"v2.9",
"v2.9-rc1",
"v2.8",
"v2.8-rc1",
"v2.7",
"v2.7-rc1",
"v2.6",
"v2.6-rc2",
"v2.6-rc1",
"v2.5",
"v2.5-rc2",
"v2.5-rc1",
"v2.4",
"v2.4-rc1",
"v2.3-rc1",
"v2.2",
"v2.2-rc2",
"v2.2-rc1",
"v2.1",
"v2.1-rc1",
"v2.0",
"v2.0-rc1",
"v1.9",
"v1.9-rc2",
"v1.9-rc1",
"v1.8",
"v1.8-rc1",
"v1.7",
"v1.7-rc2",
"v1.7-rc1",
"v1.6",
"v1.6-rc2",
"v1.6-rc1",
"v1.5",
"v1.5-rc2",
"v1.5-rc1",
"v1.4",
"v1.4-rc2",
"v1.4-rc1",
"v1.3",
"v1.3-rc2",
"v1.3-rc1",
"v1.2",
"v1.2-rc2",
"v1.2-rc1",
"v1.1",
"v1.1-rc2",
"v1.1-rc1",
"v1.0",
"v1.0-rc3",
"v1.0-rc2",
"v1.0-rc1",
"v0.4.3",
"v0.4.3-rc2",
"v0.4.3-rc1",
"v0.4.2",
"v0.4.2-rc2",
"v0.4.2-rc1",
"v0.4.1",
"v0.4.1-rc2",
"v0.4.1-rc1",
"v0.4.0",
"v0.4.0-rc3",
"v0.4.0-rc2",
"v0.4.0-rc1",
"v0.3.9",
"v0.3.9-rc2",
"v0.3.9-rc1",
"v0.3.8",
"v0.3.8-rc2",
"v0.3.8-rc1",
"v0.3.7",
"v0.3.7-rc3",
"v0.3.7-rc2",
"v0.3.7-rc1",
"v0.3.6",
"v0.3.6-rc3",
"v0.3.6-rc2",
"v0.3.6-rc1",
"v0.3.5",
"v0.3.5-rc3",
"v0.3.5-rc2",
"v0.3.5-rc1",
"v0.3.4"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53525.json"
}
}
],
"modified": "2026-10-28T02:30:26.349203747Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53525.json",
"https://github.com/weechat/weechat/security/advisories/GHSA-vhv8-g2r9-cwcc",
"https://nvd.nist.gov/vuln/detail/CVE-2026-53525"
],
"provider_metadata": {
"cwe_ids": [
"CWE-208"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53525.json"
}
},
"related_cves": [
{
"value": "CVE-2026-53525",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 492939,
"published_at": "2026-08-21T22:19:21.278+00:00"
}