Mbed TLS 3.5.0 to 3.6.5 fixed in 3.6.6 and 4.1.0 has a buffer overflow in the x509_inet_pton_ipv6() function
Conclusion & alert: CVE-2026-25833 is rated Low Risk (35.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-03 | 0.04% | 0.05% | +0.01% |
| 2 | 2026-04-02 | — | 0.04% | — |
Full EPSS history (2 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2026-25833: 1 source package rows (mbedtls); 5 state rows across 5 repos (3.20-main, 3.21-main, 3.22-main, 3.23-main, edge-main); fixed 5, open 0. | https://security.alpinelinux.org/vuln/CVE-2026-25833 |
debian
|
unimportant | CVE-2026-25833 unimportant priority: Debian including 1 source packages (mbedtls), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. | https://security-tracker.debian.org/tracker/CVE-2026-25833 |
suse
|
high | CVE-2026-25833 severity important: SUSE including 79 source package names (libeverest-3.6.6-1.1, libeverest-x86-64-v3-3.6.6-1.1, …), 814 product×package rows across 28 product lines (SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS, … (28 product lines)): Known Not Affected 803, Fixed 11. | https://www.suse.com/security/cve/CVE-2026-25833/ |
ubuntu
|
medium | CVE-2026-25833 medium priority: Ubuntu including 1 source packages (mbedtls), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): needs-triage 7. | https://ubuntu.com/security/CVE-2026-25833 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| trustedfirmware | mbed_tls | >= 3.5.0, < 3.6.6 | cpe:2.3:a:trustedfirmware:mbed_tls:*:*:*:*:*:*:*:* |
| trustedfirmware | mbed_tls | 4.0.0 | cpe:2.3:a:trustedfirmware:mbed_tls:4.0.0:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://mbed-tls.readthedocs.io/en/latest/security-advisories/ | Vendor Advisory |
| https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-inet-pton/ | Vendor Advisory |