What is CVE-2023-4527?

CVE-2023-4527 is a medium-severity vulnerability in GNU Glibc, classified under Stack-based Buffer Overflow. CVSS score: 6.5/10. Published 2023-09-18.

How severe is CVE-2023-4527?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Is CVE-2023-4527 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in GNU Glibc

CVE-2023-4527

A flaw was found in glibc. When the getaddrinfo function is called with the AF_UNSPEC address family and the system is configured with no-aaaa mode via /etc/resolv.conf, a DNS response via TCP larger than 2048 bytes can potentially disclose stack contents through the function returned address data, and may cause a crash.

Vulnerability class: Buffer Overflow

Published 2023-09-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H.

EPSS exploit prediction

EPSS: 0.017 (76.4th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 76th percentile — 76.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

RHSA-2023:5453 (vendor-advisory, Third Party Advisory)
RHSA-2023:5455 (vendor-advisory, Third Party Advisory)
access.redhat.com/security/cve/CVE-2023-4527 (Third Party Advisory, vdb-entry)
RHBZ#2234712 (issue-tracking, Exploit, Third Party Advisory, Issue Tracking)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Third Party Advisory)

Frequently asked questions

What is CVE-2023-4527?: CVE-2023-4527 is a medium-severity vulnerability in GNU Glibc, classified under Stack-based Buffer Overflow. CVSS score: 6.5/10. Published 2023-09-18.
How severe is CVE-2023-4527?: Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2023-4527 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.