Vulnerability · Published Sep 24, 2026 · Assigned by mitre
CVE-2026-73064
Low 2.9
In plain English
A low-severity security flaw in Mbed TLS from trustedfirmware. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)2.9Low
Exploit odds (30 days)0.1%top 99.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
In Mbed TLS 3.2.0 though 3.6.6 and 4.0.0 through 4.1.0, an attacker who can cause an entropy source to fail can remove or inject bytes into the start of the TLS stream. This only affects TLS 1.3 servers.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | mbedtls | no fix listed | DEBIAN-CVE-2026-73064 |
| Debian:13 | mbedtls | no fix listed | DEBIAN-CVE-2026-73064 |
| Debian:14 | mbedtls | 3.6.7-1 | DEBIAN-CVE-2026-73064 |
| Ubuntu:26.04:LTS | mbedtls | no fix listed | UBUNTU-CVE-2026-73064 |
| Ubuntu:26.10 | mbedtls | no fix listed | UBUNTU-CVE-2026-73064 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| trustedfirmware | Mbed TLS | 3.2.0 – before 3.6.74.0.0 – before 4.1.1 |
Weakness: CWE-394 · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N