Which products and versions are affected by CVE-2023-38039?

Affected: Curl (Haxx) versions >= 8.3.0; Fedora (Fedoraproject) versions 37, 38, 39; Windows 10 1809 (Microsoft), among others. The full list is in the CVE brief.

Is CVE-2023-38039 being exploited in the wild?

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

Is CVE-2023-38039 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-2023-38039?

Public exploit code is available.

Is there a fix for CVE-2023-38039?

Fixed versions are available, including Curl 7.88.1-10+deb12u14+sp999, Curl 7.88.1-10+deb12u3, Curl 8.0.1-11.71.1.

How urgently should CVE-2023-38039 be patched?

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

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Vulnerability Intelligence

CVE-2023-38039

HighPublic exploit

When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API.

Published Sep 15, 2023 · Updated Aug 17, 2026 · Also known as ALPINE-CVE-2023-38039, CURL-CVE-2023-38039, DEBIAN-CVE-2023-38039, EUVD-2023-41865, GHSA-99j9-jf36-9747, JLSEC-2026-1342, SUSE-SU-2023:3692-1, SUSE-SU-2023:3823-1, UBUNTU-CVE-2023-38039

Key Facts

Patch immediately

CVE-2023-38039 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting Curl (Haxx), Fedora (Fedoraproject), Windows 10 1809 (Microsoft) and 22 more products.
It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
EPSS estimates a 58% probability of exploitation in the next 30 days.
Fixed versions are available, including Curl 7.88.1-10+deb12u14+sp999, Curl 7.88.1-10+deb12u3, Curl 8.0.1-11.71.1.
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)

58%

Higher than 99.0% of all scored CVEs

Exploited in the wild

No known

Not in a known-exploited catalog

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2023-38039 brief as a PDF

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

Description

When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API.

However, curl did not have a limit in how many or how large headers it would accept in a response, allowing a malicious server to stream an endless series of headers and eventually cause curl to run out of heap memory.

Affected Products

106 affected entries in total

Product	Affected versions	Fixed in
CurlHaxx	>= 8.3.0	8.3.0
FedoraFedoraproject	37, 38, 39	n/a
Windows 10 1809Microsoft	See advisory	10.0.17763.5122
Windows 10 21h2Microsoft	See advisory	10.0.19044.3693
Windows 10 22h2Microsoft	See advisory	10.0.19045.3693

20 more affected products in the full CVE brief

Patched Releases

Curl

7.88.1-10+deb12u14+sp999, 7.88.1-10+deb12u3, 8.0.1-11.71.1, 8.0.1-150400.5.29.1, 8.1.2-3.ph3, 8.1.2-5.ph4, 8.1.2-5.ph5, 8.2.1-1ubuntu3, 8.3.0, 8.3.0-1, 8.3.0-1.1, 8.3.0-1.amzn2.0.1, 8.3.0-1.amzn2023.0.1, 8.3.0-r0

curl-devel

8.1.2-5.ph4, 8.1.2-5.ph5

curl-libs

8.1.2-5.ph4, 8.1.2-5.ph5

curl-minimal

8.3.0-1.amzn2023.0.1

jbcs-httpd24-curl

0:8.4.0-2.el7jbcs, 0:8.4.0-2.el8jbcs

libcurl

8.3.0-1.amzn2.0.1, 8.3.0-1.amzn2023.0.1

LibCURL_jll

8.4.0+0

libcurl-devel

8.0.1-11.71.1, 8.0.1-150400.5.29.1, 8.3.0-1.1, 8.3.0-1.amzn2.0.1, 8.3.0-1.amzn2023.0.1

libcurl-devel-32bit

8.0.1-150400.5.29.1, 8.3.0-1.1

libcurl-minimal

8.3.0-1.amzn2023.0.1

libcurl4

8.0.1-11.71.1, 8.0.1-150400.5.29.1, 8.3.0-1.1

libcurl4-32bit

8.0.1-11.71.1, 8.0.1-150400.5.29.1, 8.3.0-1.1

Windows 10 1809

10.0.17763.5122

Windows 10 21h2

10.0.19044.3693

Windows 10 22h2

10.0.19045.3693

Windows 11 21h2

10.0.22000.2600

Windows 11 22h2

10.0.22621.2715

Windows 11 23h2

10.0.22631.2715

Windows Server 2019

10.0.17763.5122

Windows Server 2022

10.0.20348.2113

mysql

8.0.35-1

rootio-curl

7.88.1-10+deb12u3, 8.3.0-1

seal-curl

7.88.1-10+deb12u14+sp999

tensorflow

2.16.1-1

Timeline

Publicly disclosed
Sep 15, 2023
Last updated
Aug 17, 2026

Weakness Type

CWE-770 Allocation of Resources Without Limits or Throttling

References

advisoryRHSA-2023:7625
advisoryRHSA-2023:7626
advisoryhttps://bugzilla.suse.com/1215026
advisoryhttps://curl.se/docs/CVE-2023-38039.html
advisoryhttp://seclists.org/fulldisclosure/2023/Oct/17

15 more references in the full CVE brief

FAQ

Common Questions.

When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API.
Affected: Curl (Haxx) versions >= 8.3.0; Fedora (Fedoraproject) versions 37, 38, 39; Windows 10 1809 (Microsoft), 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.
Public exploit code is available.
Fixed versions are available, including Curl 7.88.1-10+deb12u14+sp999, Curl 7.88.1-10+deb12u3, Curl 8.0.1-11.71.1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.

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