DEBIAN-CVE-2026-63387

Source
https://security-tracker.debian.org/tracker/CVE-2026-63387
Import Source
https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-63387.json
JSON Data
https://api.test.osv.dev/v1/vulns/DEBIAN-CVE-2026-63387
Upstream
Published
2026-08-20T18:16:36Z
Modified
2026-09-18T16:00:07Z
Severity
  • 7.0 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H CVSS Calculator
Summary
[none]
Details

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.

References

Affected packages

Debian:12 / libevent

Package

Name
libevent
Purl
pkg:deb/debian/libevent?arch=source&distro=bookworm

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.1.12-stable-8+deb12u1

Affected versions

2.*
2.1.12-stable-8

Ecosystem specific

{
    "urgency":  "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-63387.json"

Debian:13 / libevent

Package

Name
libevent
Purl
pkg:deb/debian/libevent?arch=source&distro=trixie

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.1.13-stable-1~deb13u1

Affected versions

2.*
2.1.12-stable-10

Ecosystem specific

{
    "urgency":  "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-63387.json"

Debian:14 / libevent

Package

Name
libevent
Purl
pkg:deb/debian/libevent?arch=source&distro=forky

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.1.13-stable-1

Affected versions

2.*
2.1.12-stable-10
2.1.13-stable-1~deb13u1

Ecosystem specific

{
    "urgency":  "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-63387.json"