CVE-2024-3653: Undertow: learningpushhandler can lead to remote memory dos attacks
Vulnerability summary
CVE-2024-3653 is a medium (CVSS 5.3) vulnerability in undertow. EPSS estimates a 1.87% chance of exploitation in the next 30 days, higher than 79.3% of scored vulnerabilities.
Not severe (CVSS 5.3, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 3Timeline
- 08-07-2024PublishedVulnerability first disclosed.
- 08-09-2026Last modifiedVulnerability information updated.
Description
A vulnerability was found in Undertow. This issue requires enabling the learning-push handler in the server's config, which is disabled by default, leaving the maxAge config in the handler unconfigured. The default is -1, which makes the handler vulnerable. If someone overwrites that config, the server is not subject to the attack. The attacker needs to be able to reach the server with a normal HTTP request.
CVSS metrics
6 scores · 5 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- OSV · DebianEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- OSV · MavenEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS trend
Probability
1.87%
Chance of exploitation in the next 30 days
Percentile
79%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.87% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- undertow< 2.3.18-1
Io.undertow1 product
- undertow-core≥ 2.3.0.Alpha1, < 2.3.15.Final | < 2.2.34.Final
Ubuntu1 product
- undertowAll versions (No fix recorded)
3 vendors · 3 products
