How severe is CVE-2026-5295?

CVE-2026-5295 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-5295 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-5295?

CVE-2026-5295 affects Wolfssl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-5295?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-5295 have an EU (EUVD) identifier?

Yes. CVE-2026-5295 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21228.

When was CVE-2026-5295 published?

CVE-2026-5295 was published on 2026-04-09 and last updated on 2026-06-17.

CVE-2026-5295

CVE-2026-5295 is a high-severity vulnerability in Wolfssl with a CVSS 3.x base score of 8.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-121.

Key facts

Severity: High (CVSS 3.x base score 8.0)
CVSS v4: 5.9
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21228
Weakness: CWE-121
Affected product: Wolfssl
Published: 2026-04-09
Last modified: 2026-06-17

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().

Frequently asked questions

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().
How severe is CVE-2026-5295?: CVE-2026-5295 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-5295 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-5295?: CVE-2026-5295 affects Wolfssl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-5295?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-5295 have an EU (EUVD) identifier?: Yes. CVE-2026-5295 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21228.
When was CVE-2026-5295 published?: CVE-2026-5295 was published on 2026-04-09 and last updated on 2026-06-17.

References

https://github.com/wolfSSL/wolfssl/pull/10116

Affected products (1)

cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*

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