Skip to content
Fencer Vulns
high 7.5

CVE-2023-41378 json

Calico Typha hangs during unclean TLS handshake

published 2023-11-06 3 y ago modified 2026-08-07 3 mo ago also EUVD-2023-2890 , GHSA-5r5h-q934-cccp

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits
0
none known

Summary

In certain conditions for Calico Typha (v3.26.2, v3.25.1 and below), and Calico Enterprise Typha (v3.17.1, v3.16.3, v3.15.3 and below), a client TLS handshake can block the Calico Typha server indefinitely, resulting in denial of service. The TLS Handshake() call is performed inside the main server handle for loop without any timeout allowing an unclean TLS handshake to block the main loop indefinitely while other connections will be idle waiting for that handshake to finish.

Patch / fix

  • go github.com/projectcalico/calico 3.26.3
  • projectcalico calico 3.25.2, 3.26.3
  • tigera calico_os 3.25.2, 3.26.3
  • tigera calico_enterprise 3.15.4, 3.16.4, 3.17.2
  • tigera calico_cloud 18.0.0

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.89% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
go github.com/projectcalico/calico
>=3.26.0, <3.26.3
<=3.25.1
3.26.3

Affected products

  • Calico Typha
  • Tigera Typha
  • tigera calico

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-703 Improper Check or Handling of Exceptional Conditions
  • CWE-755 Improper Handling of Exceptional Conditions

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Correcting CPE configurations for the Calico open source product to be application type rather than os. It seems the NVD folks got confused by the name calico_os and though it was an operating system.