3.7

CVE-2026-88648: gnutls28 Improper Certificate Validation

Awaiting analysis
AliasesDEBIAN-CVE-2026-88648UBUNTU-CVE-2026-88648
Published 08-10-2026Last modified 29-10-2026

Vulnerability summary

CVE-2026-88648 is a low (CVSS 3.7) Improper Certificate Validation vulnerability in gnutls28. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 9.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 3.7, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
3.7/10
010
Low · v3.1 (CVE.org)
EPSS score
0.19%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 08-10-2026
    PublishedVulnerability first disclosed.
  2. 29-10-2026
    Last modifiedVulnerability information updated.

Description

Incomplete X.509 implementation in GnuTLS v3.8.13 allows attackers controlling a subordinate Certificate Authority to bypass cross-domain PKI restrictions and issue unauthorized certificates.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.19%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

09-10-202603-11-2026

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.

Ubuntu2 products
  • gnutls26All versions (No fix recorded)
  • gnutls28All versions (No fix recorded)
Debian1 product
  • gnutls28All versions (No fix recorded)

2 vendors · 3 products

References

7 links