CVE-2026-63387

highpriority · track · 0EPSS 0.004 · 36 %ileDEFRRU

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.42% (36th) EPSS

CVSS 7 · high

Is it mine?

18 products

Check your exposure

Who says so?

3 sources

fstec_bdu · cert_bund · certfr

EPSS · scored 2026-10-28

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.0

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.4–7

v3.17highAV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:Hsecondary · FSTEC (BDU) RU

v3.17highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:Hsecondary · security-advisories@github.comexploitability 2.2 · impact 4.7

v3.16.4mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: no · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-121USCWE-121USCWE-193USCWE-193USCWE-787USCWE-787US

affected products (18)

Products and version ranges known to be affected.

Amazon Linux 2all versionscert_bundDEcpe:/o:amazon:linux_2:-
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Fedora Linuxall versionscert_bundDEcpe:/o:fedoraproject:fedora:-
IBM AIX 7.2all versionscert_bundDEcpe:/o:ibm:aix:7.2
IBM AIX 7.3all versionscert_bundDEcpe:/o:ibm:aix:7.3
IBM MQ Operatorall versionscert_bundDEcpe:/a:ibm:mq:operator
IBM QRadar SIEMall versionscert_bundDEcpe:/a:ibm:qradar_siem:-
IBM VIOS 4.1all versionscert_bundDEcpe:/a:ibm:vios:4.1
IBM iall versionscert_bundDEcpe:/o:ibm:i:-
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
RESF Rocky Linuxall versionscert_bundDEcpe:/o:resf:rocky_linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Red Hat Enterprise Linux 9all versionscert_bundDEcpe:/o:redhat:enterprise_linux:9
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
SUSE openSUSEall versionscert_bundDEcpe:/o:suse:opensuse:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Libevent project Libevent≤ 2.1.12fstec_bduRU
Libevent project Libevent≤ 2.2.1-alphafstec_bduRU

advisories (3)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-3419Red Hat Enterprise Linux (corosync, libevent, libsoup): Mehrere SchwachstellenDeutsch2026-09-16csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen oder Denial-of-Service-Zustände herbeizuführen.
CERTFR-2026-AVI-1336Multiples vulnérabilités dans les produits IBMFrançais2026-10-16vendor · certfrFR
CERTFR-2026-AVI-1378Multiples vulnérabilités dans les produits IBMFrançais2026-10-23vendor · certfrFR

also known as (2)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

fstec_bdu cert_bund certfr NVD CVE.org MITRE

published 2026-08-20modified 2026-10-26

references (3) nvd

External citations — patches, advisories, analysis.

scry

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