CVE-2026-0819
Description
A stack buffer overflow vulnerability exists in wolfSSL's PKCS7 SignedData encoding functionality. In wc_PKCS7_BuildSignedAttributes(), when adding custom signed attributes, the code passes an incorrect capacity value (esd->signedAttribsCount) to EncodeAttributes() instead of the remaining available space in the fixed-size signedAttribs[7] array. When an application sets pkcs7->signedAttribsSz to a value greater than MAX_SIGNED_ATTRIBS_SZ (default 7) minus the number of default attributes already added, EncodeAttributes() writes beyond the array bounds, causing stack memory corruption. In WOLFSSL_SMALL_STACK builds, this becomes heap corruption. Exploitation requires an application that allows untrusted input to control the signedAttribs array size when calling wc_PKCS7_EncodeSignedData() or related signing functions.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| debian | bookworm | affected | |
| debian | bullseye | affected | |
| debian | forky | fixed | 5.9.0-0.1 |
| debian | sid | fixed | 5.9.0-0.1 |
| debian | trixie | affected | |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| wolfssl | wolfssl | {"startIncluding":"5.5.0","endExcluding":"5.9.0"} | 5.9.0 |
References
CWEs
CWE-121 CWE-787
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.