CVE-2019-17638: eclipse jetty
Vulnerability summary
CVE-2019-17638 is a critical (CVSS 9.4) vulnerability in eclipse jetty. EPSS estimates a 11.14% chance of exploitation in the next 30 days, higher than 95.9% of scored vulnerabilities.
Severe, CVSS 9.4 (NVD); no exploitation reported by the 5 checked sources; EPSS 11% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 3Timeline
- 09-07-2020PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
Description
In Eclipse Jetty, versions 9.4.27.v20200227 to 9.4.29.v20200521, in case of too large response headers, Jetty throws an exception to produce an HTTP 431 error. When this happens, the ByteBuffer containing the HTTP response headers is released back to the ByteBufferPool twice. Because of this double release, two threads can acquire the same ByteBuffer from the pool and while thread1 is about to use the ByteBuffer to write response1 data, thread2 fills the ByteBuffer with other data. Thread1 then proceeds to write the buffer that now contains different data. This results in client1, which issued request1 seeing data from another request or response which could contain sensitive data belonging to client2 (HTTP session ids, authentication credentials, etc.). If the Jetty version cannot be upgraded, the vulnerability can be significantly reduced by configuring a responseHeaderSize significantly larger than the requestHeaderSize (12KB responseHeaderSize and 8KB requestHeaderSize).
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated9.4CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
- OSV · DebianEcosystem advisory · calculated9.4CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
- OSV · MavenEcosystem advisory · calculated9.4CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
EPSS trend
Probability
11.14%
Chance of exploitation in the next 30 days
Percentile
96%
Versus all other CVEs
30-day change
No change 0.00 pp
From 11.14% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-672Operation on a Resource after Expiration or ReleaseThe product uses, accesses, or otherwise operates on a resource after that resource has been expired, released, or revoked.
- CWE-675Multiple Operations on Resource in Single-Operation ContextThe product performs the same operation on a resource two or more times, when the operation should only be applied once.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- jetty9< 9.4.31-1
Eclipse1 product
- jettyEOL9.4.27:20200227 | 9.4.28:20200408 | 9.4.29:20200521
Org.eclipse.jetty1 product
- jetty-server≥ 9.4.27, < 9.4.30.v20200611
The eclipse foundation1 product
- eclipse jetty9.4.27.v20200227 to 9.4.29.v20200521
Ubuntu1 product
- jetty9< 9.4.45-1 | < 9.4.53-1 | < 9.4.56-1
5 vendors · 5 products