VDB
CVE-2026-5503
CVE-2026-5503
PUBLISHED
CVSS 6.9 MEDIUM
Reported by wolfSSL · Published April 9, 2026
In TLSX_EchChangeSNI, the ctx->extensions branch set extensions unconditionally even when TLSX_Find returned NULL. This caused TLSX_UseSNI to attach the attacker-controlled publicName to the shared WOLFSSL_CTX when no inner SNI was configured. TLSX_EchRestoreSNI then failed to clean it up because its removal was gated on serverNameX != NULL. The inner ClientHello was sized before the pollution but written after it, causing TLSX_SNI_Write to memcpy 255 bytes past the allocation boundary.
EPSS 0.05% · 16.9th percentile
Risk Scores
CVSS v4.0
6.9
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
EPSS Score
0.05%
16.9th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| wolfSSL | wolfSSL | 0 |
| wolfSSL | wolfSSL | 0 |
Timeline
- Apr 9, 2026 CVE Published
- Apr 10, 2026 EPSS Score
- May 18, 2026 EPSS Score
- May 19, 2026 EPSS Score
- May 20, 2026 EPSS Score
- May 21, 2026 EPSS Score
- May 22, 2026 EPSS Score
- May 23, 2026 EPSS Score
- May 24, 2026 EPSS Score
- May 25, 2026 EPSS Score
- May 26, 2026 EPSS Score
- May 27, 2026 EPSS Score