3.3

CVE-2026-4159: wc_PKCS7_DecodeEnvelopedData 1 byte out-of-bounds read

Analyzed
AliasesUBUNTU-CVE-2026-4159DEBIAN-CVE-2026-4159ALPINE-CVE-2026-4159
Published 19-03-2026Last modified 20-03-2026

Vulnerability summary

CVE-2026-4159 is a low (CVSS 3.3) Out-of-bounds Read vulnerability in wolfssl. EPSS estimates a 0.10% chance of exploitation in the next 30 days, higher than 0.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 1.2, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
3.3/10
010
Low · v3.1 (NVD)
EPSS score
0.10%
0%100%
Low · -0.04 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 19-03-2026
    PublishedVulnerability first disclosed.
  2. 20-03-2026
    Last modifiedVulnerability information updated.

Description

1-byte OOB heap read in wc_PKCS7_DecodeEnvelopedData via zero-length encrypted content. A vulnerability existed in wolfSSL 5.8.4 and earlier, where a 1-byte out-of-bounds heap read in wc_PKCS7_DecodeEnvelopedData could be triggered by a crafted CMS EnvelopedData message with zero-length encrypted content. Note that PKCS7 support is disabled by default.

CVSS metrics

7 scores · 5 sources · 2 versions

EPSS trend

Probability

0.10%

Chance of exploitation in the next 30 days

Percentile

1%

Versus all other CVEs

30-day change

Decrease -0.04 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: local access, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine1 product
  • wolfssl< 5.9.1-r0 | < 5.9.0-r0
Debian1 product
  • wolfsslAll versions (No fix recorded)
Ubuntu1 product
  • wolfsslAll versions (No fix recorded)
Wolfssl1 product

4 vendors · 4 products

References

5 links