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CVE-2026-5295: Stack Buffer Overflow in wolfSSL PKCS7 wc_PKCS7_DecryptOri() via Oversized OID

Analyzed
AliasesUBUNTU-CVE-2026-5295DEBIAN-CVE-2026-5295ALPINE-CVE-2026-5295
Published 09-04-2026Last modified 14-04-2026

Vulnerability summary

CVE-2026-5295 is a high (CVSS 8.0) Stack-based Buffer Overflow vulnerability in wolfssl. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.9, adjacent network); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
8.0/10
010
High · v3.1 (NVD)
EPSS score
0.18%
0%100%
Low · -0.10 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. 14-04-2026
    Last modifiedVulnerability information updated.

Description

A stack buffer overflow exists in wolfSSL's PKCS7 implementation in the wc_PKCS7_DecryptOri() function in wolfcrypt/src/pkcs7.c. When processing a CMS EnvelopedData message containing an OtherRecipientInfo (ORI) recipient, the function copies an ASN.1-parsed OID into a fixed 32-byte stack buffer (oriOID[MAX_OID_SZ]) via XMEMCPY without first validating that the parsed OID length does not exceed MAX_OID_SZ. A crafted CMS EnvelopedData message with an ORI recipient containing an OID longer than 32 bytes triggers a stack buffer overflow. Exploitation requires the library to be built with --enable-pkcs7 (disabled by default) and the application to have registered an ORI decrypt callback via wc_PKCS7_SetOriDecryptCb().

CVSS metrics

7 scores · 5 sources · 2 versions

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

Decrease -0.10 pp

From 0.27% 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, 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