4.3

CVE-2026-5448: 1-2 Byte Buffer Overflow in wolfSSL_X509_notAfter/notBefore

Analyzed
AliasesUBUNTU-CVE-2026-5448DEBIAN-CVE-2026-5448ALPINE-CVE-2026-5448
Published 09-04-2026Last modified 10-04-2026

Vulnerability summary

CVE-2026-5448 is a medium (CVSS 4.3) Heap-based Buffer Overflow vulnerability in wolfssl. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 23.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 2.3, adjacent network); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
4.3/10
010
Medium · v3.1 (NVD)
EPSS score
0.30%
0%100%
Low · +0.18 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 09-04-2026
    PublishedVulnerability first disclosed.
  2. 10-04-2026
    Last modifiedVulnerability information updated.

Description

X.509 date buffer overflow in wolfSSL_X509_notAfter / wolfSSL_X509_notBefore. A buffer overflow may occur when parsing date fields from a crafted X.509 certificate via the compatibility layer API. This is only triggered when calling these two APIs directly from an application, and does not affect TLS or certificate verify operations in wolfSSL.

CVSS metrics

7 scores · 5 sources · 2 versions

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

23%

Versus all other CVEs

30-day change

Increase +0.18 pp

From 0.13% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: adjacent network, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine1 product
  • wolfssl< 5.9.1-r0
Debian1 product
  • wolfsslAll versions (No fix recorded)
Ubuntu1 product
  • wolfsslAll versions (No fix recorded)
Wolfssl1 product

4 vendors · 4 products

References

5 links