cbcvebase.
CVE-2026-3549
published 2026-03-19

CVE-2026-3549: Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing…

PriorityP350critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.49%
39.1th percentile
Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving.

Affected

6 ranges
VendorProductVersion rangeFixed in
debianwolfssl< wolfssl 5.9.0-0.1 (forky)wolfssl 5.9.0-0.1 (forky)
msrcazl3_mariadb_10.11.16-1_on_azure_linux_3.0
msrccbl2_mariadb_10.6.24-1_on_cbl_mariner_2.0
wofsslwolfssl< 5.9.05.9.0
wolfsslwolfssl< 5.9.05.9.0
wolfsslwolfssl>= 0 < 5.9.0-0.15.9.0-0.1

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv4.08.3HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
osv8.3HIGH
vendor_debian8.3HIGH
vendor_msrc8.3HIGH
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