Which products and versions are affected by CVE-2023-39456?

Affected: Traffic Server (Apache) versions >= 9.0.0; Fedora (Fedoraproject) versions 37, 38; trafficserver9 (alpine), among others. The full list is in the CVE brief.

Is CVE-2023-39456 being exploited in the wild?

It is not listed in any known-exploited vulnerabilities catalog.

Is CVE-2023-39456 in the CISA KEV catalog?

No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

Is there a public exploit for CVE-2023-39456?

No public exploit code is known.

Is there a fix for CVE-2023-39456?

Fixed versions are available, including Traffic Server 9.2.3, trafficserver 9.2.3+ds-1, trafficserver 9.2.3+ds-1+deb12u1.

How urgently should CVE-2023-39456 be patched?

Brandefense priority: patch immediately, because it is very likely to be exploited soon.

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Vulnerability Intelligence

CVE-2023-39456

High

Improper Input Validation vulnerability in Apache Traffic Server with malformed HTTP/2 frames.This issue affects Apache Traffic Server: from 9.0.0 through 9.2.2.

Published Oct 17, 2023 · Updated Oct 8, 2026 · Also known as DEBIAN-CVE-2023-39456, UBUNTU-CVE-2023-39456

Key Facts

Patch immediately

CVE-2023-39456 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting Traffic Server (Apache), Fedora (Fedoraproject), trafficserver9 (alpine) and 1 more product.
It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
EPSS estimates a 61% probability of exploitation in the next 30 days.
Fixed versions are available, including Traffic Server 9.2.3, trafficserver 9.2.3+ds-1, trafficserver 9.2.3+ds-1+deb12u1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.

CVSS v3.1

7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS (30-day exploit likelihood)

61%

Higher than 99.1% of all scored CVEs

Exploited in the wild

No known

Not in a known-exploited catalog

Public exploit code

None known

Get the full CVE-2023-39456 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

Improper Input Validation vulnerability in Apache Traffic Server with malformed HTTP/2 frames.This issue affects Apache Traffic Server: from 9.0.0 through 9.2.2.

Users are recommended to upgrade to version 9.2.3, which fixes the issue.

Affected Products

16 affected entries in total

Product	Affected versions	Fixed in
Traffic ServerApache	>= 9.0.0	9.2.3
FedoraFedoraproject	37, 38	n/a
trafficserver9alpine	See advisory	9.2.3-r0
trafficserverdebian	See advisory	9.2.3+ds-1+deb12u1

Patched Releases

Traffic Server

9.2.3

trafficserver

9.2.3+ds-1, 9.2.3+ds-1+deb12u1

trafficserver9

9.2.3-r0

Timeline

Publicly disclosed
Oct 17, 2023
Last updated
Oct 8, 2026

Weakness Type

CWE-20 Improper Input Validation

References

5 more references in the full CVE brief

FAQ

Common Questions.

Improper Input Validation vulnerability in Apache Traffic Server with malformed HTTP/2 frames.This issue affects Apache Traffic Server: from 9.0.0 through 9.2.2.
Affected: Traffic Server (Apache) versions >= 9.0.0; Fedora (Fedoraproject) versions 37, 38; trafficserver9 (alpine), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Traffic Server 9.2.3, trafficserver 9.2.3+ds-1, trafficserver 9.2.3+ds-1+deb12u1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.

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