What is CVE-2026-5295?
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().
The record classifies CVE-2026-5295 under weakness class CWE-121. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 184 days ago.
Severity and exploitation probability
- CVSS v4.0 base score
- 5.9 — Medium (derived from score)
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N - EPSS (FIRST)
- 0.2% probability of exploitation in the next 30 days, higher than 18.0% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 5.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-04-09, last modified 2026-04-14
Is CVE-2026-5295 being exploited?
Weaponised exploit code for CVE-2026-5295 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 18 in the Threadlinqs vulnerability feed.
- trickest/cve (trickest)
Affected products and versions
- wolfSSL: wolfSSL
How to fix CVE-2026-5295
No vendor patch reference has been recorded for CVE-2026-5295 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-5295
1 tracked threat in the Threadlinqs corpus references CVE-2026-5295, either in the campaign’s CVE list or as an indicator on the campaign record.
- Multiple WolfSSL Critical Vulnerabilities: Certificate Bypass, RCE, and Post-Quantum Weakening — CRITICAL · 2026-06-30
Sources
Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on .