8.3

CVE-2026-89136: Client accepts unsolicited RawPublicKey server certificate type

Awaiting analysis
AliasesUBUNTU-CVE-2026-89136DEBIAN-CVE-2026-89136ALPINE-CVE-2026-89136
Published 27-09-2026Last modified 29-09-2026

Vulnerability summary

CVE-2026-89136 is a high (CVSS 8.3) Improper Authentication vulnerability in wolfssl. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 32.5% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 8.3 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
8.3/10
010
High · v4.0 (CVE.org)
EPSS score
0.38%
0%100%
Low · -0.17 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 27-09-2026
    PublishedVulnerability first disclosed.
  2. 29-09-2026
    Last modifiedVulnerability information updated.

Description

When using RPK (Raw Public Key), the client side of a TLS 1.2, 1.3 and DTLS 1.2 connection could accept an unsolicited server_cert_type=RawPublicKey which allowed a malicious or misbehaving server to bypass authentication. RPK is off by default and only enabled in --enable-rpk OR --enable-all OR --enable-distro AKA HAVE_RPK builds.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.38%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

Decrease -0.17 pp

From 0.55% 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: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine1 product
  • wolfssl< 5.9.4-r0
Debian1 product
  • wolfsslAll versions (No fix recorded)
Ubuntu1 product
  • wolfsslAll versions (No fix recorded)
Wolfssl1 product

4 vendors · 4 products

References

5 links