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Fencer Vulns
high 7.5

CVE-2026-25833 json

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

published 2026-04-01 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-17997

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits
0
none known

Summary

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

Patch / fix

  • trustedfirmware mbed_tls 3.6.6
  • mbedtls Debian 14 3.6.6-0.1

debian advisories DEBIAN-CVE-2026-25833

  • ovmf SLES for SAP applications 16.0, SLES 16.0 202502-160000.5.1

suse advisories SUSE-SU-2026:22016-1

  • mbedtls openSUSE Leap 16.0 3.6.6-bp160.1.1
  • ovmf openSUSE Tumbleweed 202602-9.1
  • mbedtls openSUSE Tumbleweed 3.6.6-1.1

opensuse advisories openSUSE-SU-2026:21144-1openSUSE-SU-2026:10615-1openSUSE-SU-2026:10498-1

  • mbedtls Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 3.6.6-r0
  • mbedtls3 Alpine 3.24 3.6.6-r0

alpine advisories ALPINE-CVE-2026-25833

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-25833 updated cvss 7.5

mbedtls: buffer underflow in x509_inet_pton_ipv6()

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness
  • CWE-121 Stack-based Buffer Overflow

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.