CVE-2026-55958
is CVE-2026-55958real, exploitable, or a false positive? Here's the community verdict.
signals
public sources
High CVSS base score, but low real-world exploitation probability (EPSS). Likely less urgent than the score implies.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Out-of-bounds write in the Renesas TSIP TLS 1.3 transcript buffer. In tsip_StoreMessage() the capacity check guarding the fixed message bag (MSGBAG_SIZE) sets an error code but fails to return, so execution falls through to an XMEMCPY that writes past the end of the buffer once the accumulated TLS 1.3 handshake transcript exceeds MSGBAG_SIZE (8 KB), corrupting adjacent heap state and potentially causing a remote denial of service crash. The bag is sized to hold a normal handshake, so this is reached only by an unusually large but valid certificate chain, or by a malicious or man-in-the-middle server sending an oversized handshake message to a client that does not strictly verify the chain. This only affects builds using the Renesas TSIP TLS port (WOLFSSL_RENESAS_TSIP_TLS) as a TLS 1.3 client on Renesas MCUs with TSIP hardware enabled, and is rated High within those builds. All other configurations are unaffected.
References
Published
Embed this verdict
[](https://www.truepositive.app/cve/CVE-2026-55958)<a href="https://www.truepositive.app/cve/CVE-2026-55958"><img src="https://www.truepositive.app/cve/CVE-2026-55958/badge.svg" alt="TruePositive verdict for CVE-2026-55958"></a>Live badge that updates automatically as the community verdict changes.
Community ground truth
Be the first practitioner to weigh in
So far this is only TruePositive's editorial baseline from public sources. Add your real-world verdict below — it becomes the signal the next person triaging this relies on.
🥇 The first 50 practitioners to contribute earn a Founding Contributor badge.
In your experience, is this finding real and exploitable?
0 verdictsNo account needed. Anonymous verdicts post as an unverified signal. Log in to make yours verified and earn reputation.
Field notes & remediation
Verdicts are the quick signal. Notes are the evidence and fixes behind them.
No notes yet. Be the first to share what you saw, or a fix that worked.