CVE-2023-36478 | HTTP/2 HPACK integer overflow and buffer allocation

Exp

Eclipse Jetty provides a web server and servlet container. In versions 11.0.0 through 11.0.15, 10.0.0 through 10.0.15, and 9.0.0 through 9.4.52, an integer overflow in `MetaDataBuilder.checkSize` allows for HTTP/2 HPACK header values to exceed their size limit. `MetaDataBuilder.java` determines if a header name or value exceeds the size limit, and throws an exception if the limit is exceeded. However, when length is very large and huffman is true, the multiplication by 4 in line 295 will overflow, and length will become negative. `(_size+length)` will now be negative, and the check on line 296 will not be triggered. Furthermore, `MetaDataBuilder.checkSize` allows for user-entered HPACK header value sizes to be negative, potentially leading to a very large buffer allocation later on when the user-entered size is multiplied by 2. This means that if a user provides a negative length value (or, more precisely, a length value which, when multiplied by the 4/3 fudge factor, is negative), and this length value is a very large positive number when multiplied by 2, then the user can cause a very large buffer to be allocated on the server. Users of HTTP/2 can be impacted by a remote denial of service attack. The issue has been fixed in versions 11.0.16, 10.0.16, and 9.4.53. There are no known workarounds.

Published: 2023-10-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-36478 is rated High Exploit Risk (77.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.75%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.89% over the last day, indicating growing attacker interest. Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-36478

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-36478

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.87% 3.75% +1.89%
2 2026-06-06 1.85% 1.87% +0.02%
3 2026-06-02 1.85%

Full EPSS history (53 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-36478

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-36478

GitHub Security Advisory for CVE-2023-36478

GHSA-wgh7-54f2-x98r · Severity: high · Ecosystem: maven — HTTP/2 HPACK integer overflow and buffer allocation

OS Trackers for CVE-2023-36478

vendor priority summary link
alpine CVE-2023-36478: 1 source package rows (jetty-runner); 6 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 6, open 0. https://security.alpinelinux.org/vuln/CVE-2023-36478
debian not yet assigned CVE-2023-36478 not yet assigned priority: Debian including 1 source packages (jetty9), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-36478
redhat high https://access.redhat.com/security/cve/CVE-2023-36478
suse high CVE-2023-36478 severity important: SUSE including 58 source package names (jetty-annotations-9.4.53-1.1, jetty-annotations-9.4.53-150200.3.22.1, …), 234 product×package rows across 21 product lines (Image server-image, SUSE Enterprise Storage 7.1, … (21 product lines)): Fixed 234. https://www.suse.com/security/cve/CVE-2023-36478/
ubuntu medium CVE-2023-36478 medium priority: Ubuntu including 1 source packages (jetty), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 8, needs-triage 3, ignored 1. https://ubuntu.com/security/CVE-2023-36478

Affected software / configurations for CVE-2023-36478

Vendor Product Version Raw CPE
eclipse jetty >= 9.3.0, < 9.4.53 cpe:2.3:a:eclipse:jetty:*:*:*:*:*:*:*:*
eclipse jetty >= 10.0.0, < 10.0.16 cpe:2.3:a:eclipse:jetty:*:*:*:*:*:*:*:*
eclipse jetty >= 11.0.0, < 11.0.16 cpe:2.3:a:eclipse:jetty:*:*:*:*:*:*:*:*
jenkins jenkins < 2.414.3 cpe:2.3:a:jenkins:jenkins:*:*:*:*:lts:*:*:*
jenkins jenkins < 2.428 cpe:2.3:a:jenkins:jenkins:*:*:*:*:-:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
debian debian_linux 12.0 cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*

References for CVE-2023-36478

URL Tags
http://www.openwall.com/lists/oss-security/2023/10/18/4 Mailing List Third Party Advisory
https://github.com/eclipse/jetty.project/pull/9634 Issue Tracking Patch
https://github.com/eclipse/jetty.project/releases/tag/jetty-10.0.16 Release Notes
https://github.com/eclipse/jetty.project/releases/tag/jetty-11.0.16 Release Notes
https://github.com/eclipse/jetty.project/releases/tag/jetty-9.4.53.v20231009 Release Notes
https://github.com/eclipse/jetty.project/security/advisories/GHSA-wgh7-54f2-x98r Exploit Vendor Advisory
https://lists.debian.org/debian-lts-announce/2023/10/msg00045.html Mailing List
https://security.netapp.com/advisory/ntap-20231116-0011/ Third Party Advisory
https://security.netapp.com/advisory/ntap-20240621-0006/
https://www.debian.org/security/2023/dsa-5540 Third Party Advisory
cvelogic Threat Intelligence