CVE-2026-5503
CVE-2026-5503 · out-of-bounds write in TLSX_EchChangeSNI via attacker-controlled publicName
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 6.9 · Medium · EPSS 0.5%
- Published
- Updated
Stack: system
Affected products and versions
wolfssl
- Versions
- ≥ 0, ≤ 5.9.0: Affected (semver)
No fix published
wolfssl Debian:12
- Versions
- 5.5.4-2
- 5.5.4-2+deb12u1
- 5.5.4-2+deb12u2
- 5.5.4-2+deb12u3
- 5.5.4-2.1
- 5.6.4-1
- 5.6.4-2
- 5.6.6-1
- 5.6.6-1.1
- 5.6.6-1.2
- 5.6.6-1.3
- 5.6.6-1.3~exp1
- 5.7.0-0.1
- 5.7.0-0.2
- 5.7.0-0.3
- 5.7.2-0.1
- 5.7.2-0.2
- 5.7.2-0.3
- 5.7.2-0.4
- 5.8.2-1
- 5.8.2-1.1
- 5.8.2-1.2
- 5.8.4-1
- 5.9.0-0.1
- 5.9.0-0.2
- 5.9.1-0.1
- 5.9.2-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Debian:13
- Versions
- 5.7.2-0.1
- 5.7.2-0.1+deb13u1
- 5.7.2-0.1+deb13u2
- 5.7.2-0.2
- 5.7.2-0.3
- 5.7.2-0.4
- 5.8.2-1
- 5.8.2-1.1
- 5.8.2-1.2
- 5.8.4-1
- 5.9.0-0.1
- 5.9.0-0.2
- 5.9.1-0.1
- 5.9.2-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:16.04:LTS
- Versions
- 3.4.8+dfsg-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:18.04:LTS
- Versions
- 3.10.2+dfsg-2
- 3.12.0+dfsg-1
- 3.12.2+dfsg-1
- 3.13.0+dfsg-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:20.04:LTS
- Versions
- 4.1.0+dfsg-2
- 4.2.0+dfsg-1
- 4.2.0+dfsg-2
- 4.2.0+dfsg-3
- 4.3.0+dfsg-2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:22.04:LTS
- Versions
- 4.6.0-3
- 5.0.0-1
- 5.1.1-1
- 5.2.0-1
- 5.2.0-2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:24.04:LTS
- Versions
- 5.5.4-2
- 5.5.4-2.1
- 5.6.4-2
- 5.6.6-1.2
- 5.6.6-1.3
- 5.6.6-1.3build1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:25.10
- Versions
- 5.7.2-0.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:26.10
- Versions
- 5.9.1-0.1
- 5.9.2-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:26.04:LTS
- Versions
- 5.7.2-0.1
- 5.8.2-1.2
- 5.8.4-1
- 5.9.1-0.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published