Client memory disclosure via unmasked WebSocket frame
Published Jul 14, 2026 · Updated Jul 14, 2026
Out-of-bounds read in libsoup3 in Red Hat Enterprise Linux 10 allows remote attackers to expose client memory via a crafted frame. The WebSocket parser applies its payload-length overflow guard only to masked frames, so an unmasked server frame near UINT64_MAX bypasses the check before buffer-length arithmetic. Exploitation requires a libsoup-based client connected to a malicious server with max_incoming_payload_size set to 0; the resulting read exposes memory or interrupts the client process.
Summary
What happened
Out-of-bounds read in libsoup3 in Red Hat Enterprise Linux 10 allows remote attackers to expose client memory via a crafted frame. The WebSocket parser applies its payload-length overflow guard only to masked frames, so an unmasked server frame near UINT64_MAX bypasses the check before buffer-length arithmetic. Exploitation requires a libsoup-based client connected to a malicious server with max_incoming_payload_size set to 0; the resulting read exposes memory or interrupts the client process.
The record
- CVE
- CVE-2026-12478
- Published
- Jul 14, 2026
- Updated
- Jul 14, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 10
- Classifications
- CWE-125
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 14, 2026CVE publishedPublication date reported by the CVE source.
- Jul 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
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Your stack
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