Detections
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Echo: libevent: security update to 2.1.12-stable-10+e1

high Tenable Cloud Security Plugin ID 458641

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an off-by-one
 stack buffer overflow in evdns.c when dnsname_to_labels formats a name-bearing DNS record at the end of
 the 64 KB stack buffer allocated by evdns_server_request_format_response. The final-label check permits j
 plus label_len plus one to equal buf_len, after which the terminating null byte is written to
 buf[buf_len]. A crafted DNS server response containing PTR, CNAME, MX, NS, or SOA data can trigger the
 one-byte out-of-bounds write and crash or corrupt the process. This issue is fixed in versions 2.1.13 and
 2.2.2-alpha. (CVE-2026-63387)

Solution

Update the libevent library and its related packages to version 2.1.12-stable-10+e1 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-63387

Plugin Details

Severity: High

ID: 458641

Version: Revision 1.2

Type: Local

Published: 10/2/2026

Updated: 10/5/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3.9

Percentile: 52.44

CVSS v2

Risk Factor: Medium

Base Score: 6.6

Temporal Score: 4.9

Vector: CVSS2#AV:N/AC:H/Au:N/C:P/I:P/A:C

CVSS Score Source: CVE-2026-63387

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.1

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 8/21/2026

Vulnerability Publication Date: 8/20/2026

Reference Information

CVE: CVE-2026-63387