Medium
libsoup3 — security advisory
The fix for CVE-2026-0716 (commit 6ff7ef0, libsoup 3.6.6) placed the integer overflow guard inside the if (masked) block, leaving unmasked server-to-client frames unprotected. A malicious WebSocket server can send a crafted unmasked frame with a payload length near UINT64_MAX to trigger an OOB read in a libsoup-based client when max_incoming_payload_size is set to 0.
- Products
- libsoup3
- Affected versions
- 3.0.4-2, 3.0.4-3, 3.0.5-1, 3.0.7-0ubuntu1, 3.0.7-0ubuntu1+esm1, 3.0.7-0ubuntu1+esm2, 3.0.7-0ubuntu1+esm3, 3.0.7-0ubuntu1+esm4, 3.0.7-0ubuntu1+esm5, 3.0.7-0ubuntu1+esm6, 3.0.7-0ubuntu1+esm7, 3.0.7-0ubuntu1+esm8, 3.0.7-0ubuntu1+esm9, 3.4.2-4, 3.4.4-1, 3.4.4-2, 3.4.4-4, 3.4.4-5, 3.4.4-5build1, 3.4.4-5build2, 3.4.4-5ubuntu0.1, 3.4.4-5ubuntu0.2, 3.4.4-5ubuntu0.3, 3.4.4-5ubuntu0.4, 3.4.4-5ubuntu0.5, 3.4.4-5ubuntu0.6, 3.4.4-5ubuntu0.7, 3.4.4-5ubuntu0.8, 3.4.4-5ubuntu0.9, 3.6.5-4, 3.6.5-5, 3.6.5-6, 3.6.5-7, 3.6.5-9, 3.6.6-1, 3.6.6-1ubuntu0.1, 3.6.6-1ubuntu3
- Fixed versions
- Not specified
- CVEs
- CVE-2026-12478
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 17:40 UTC · Revision 1
Source evidence
The fix for CVE-2026-0716 (commit 6ff7ef0, libsoup 3.6.6) placed the integer overflow guard inside the if (masked) block, leaving unmasked server-to-client frames unprotected. A malicious WebSocket server can send a crafted unmasked frame with a payload length near UINT64_MAX to trigger an OOB read in a libsoup-based client when max_incoming_payload_size is set to 0.
osv:UBUNTU-CVE-2026-12478
libsoup3
Fixed versions: Not specified
libsoup3
Fixed versions: Not specified
libsoup3
Fixed versions: Not specified
libsoup3
Fixed versions: Not specified
Complete source record
{
"id": "b5ba9cd6210a406a25728c26327421e7fe818e82c628c170c25f99d34ad8ef8f",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-12478",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-12478",
"summary": "The fix for CVE-2026-0716 (commit 6ff7ef0, libsoup 3.6.6) placed the integer overflow guard inside the if (masked) block, leaving unmasked server-to-client frames unprotected. A malicious WebSocket server can send a crafted unmasked frame with a payload length near UINT64_MAX to trigger an OOB read in a libsoup-based client when max_incoming_payload_size is set to 0.",
"evidence": "osv:UBUNTU-CVE-2026-12478",
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"aliases": [
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],
"metrics": [
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"type": "CVSS_V3",
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{
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"affected": [
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"package": {
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},
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"3.0.4-3",
"3.0.5-1",
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"3.0.7-0ubuntu1+esm2",
"3.0.7-0ubuntu1+esm3",
"3.0.7-0ubuntu1+esm4",
"3.0.7-0ubuntu1+esm5",
"3.0.7-0ubuntu1+esm6",
"3.0.7-0ubuntu1+esm7",
"3.0.7-0ubuntu1+esm8",
"3.0.7-0ubuntu1+esm9"
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],
"modified": "2026-10-22T04:30:59.441580151Z",
"provider": "osv",
"upstream": [
"CVE-2026-12478"
],
"references": [
"https://ubuntu.com/security/CVE-2026-12478",
"https://www.cve.org/CVERecord?id=CVE-2026-12478",
"https://access.redhat.com/security/cve/CVE-2026-12478",
"https://access.redhat.com/security/cve/cve-2026-0716",
"https://bugzilla.redhat.com/show_bug.cgi?id=2489655",
"https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/518"
]
},
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{
"value": "CVE-2026-12478",
"evidence": "/upstream"
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],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 404315,
"published_at": "2026-07-14T10:16:00+00:00"
}