Vulnerability in Golang Go

CVE-2023-39326

A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body. A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request. Chunk extensions are a little-used HTTP feature which permit including additional metadata in a request or response body sent using the chunked encoding. The net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real body to encoded bytes grows too small.

EPSS: 0.012 (65.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-39326?
CVE-2023-39326 is a medium-severity vulnerability in Golang Go, classified under CWE-400: UNCONTROLLED RESOURCE CONSUMPTION. CVSS score: 5.3/10. Published 2023-12-06.
How severe is CVE-2023-39326?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2023-39326 known to be exploited?
4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.