CVE-2025-53506
Description
Uncontrolled Resource Consumption vulnerability in Apache Tomcat if an HTTP/2 client did not acknowledge the initial settings frame that reduces the maximum permitted concurrent streams. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.8, from 10.1.0-M1 through 10.1.42, from 9.0.0.M1 through 9.0.106. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Other EOL versions may also be affected. Users are recommended to upgrade to version 11.0.9, 10.1.43 or 9.0.107, which fix the issue.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 10.1.52-1~deb13u1 |
| sid | Fixed | 10.1.46-1 |
| forky | Fixed | 10.1.46-1 |
| bullseye | Fixed | 9.0.107-0+deb11u1 |
| bookworm | Fixed | 10.1.52-1~deb12u1 |
Red Hat Fixed 2 releases
| Version | Status | Fixed in |
|---|---|---|
| 9 | Fixed | — |
| 8 | Fixed | — |
Rocky Linux Fixed 2 releases
| Version | Status | Fixed in |
|---|---|---|
| 9 | Fixed | — |
| 8 | Fixed | — |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Maven | org.apache.tomcat:tomcat-coyote | >=11.0.0-M1,<11.0.9 | 11.0.9 |
| Maven | org.apache.tomcat:tomcat-coyote | >=10.1.0-M1,<10.1.43 | 10.1.43 |
| Maven | org.apache.tomcat:tomcat-coyote | >=9.0.0.M1,<9.0.107 | 9.0.107 |
| Maven | org.apache.tomcat:tomcat-coyote | >=8.5.0,<=8.5.100 | |
| Maven | org.apache.tomcat.embed:tomcat-embed-core | >=8.5.0,<=8.5.100 | |
| Maven | org.apache.tomcat.embed:tomcat-embed-core | >=9.0.0.M1,<9.0.107 | 9.0.107 |
| Maven | org.apache.tomcat.embed:tomcat-embed-core | >=10.1.0-M1,<10.1.43 | 10.1.43 |
| Maven | org.apache.tomcat.embed:tomcat-embed-core | >=11.0.0-M1,<11.0.9 | 11.0.9 |
References
- https://access.redhat.com/errata/RHSA-2025:14181
- https://errata.rockylinux.org/RLSA-2025:14177
- https://nvd.nist.gov/vuln/detail/CVE-2025-53506
- https://github.com/apache/tomcat/commit/2aa6261276ebe50b99276953591e3a2be7898bdb
- https://github.com/apache/tomcat/commit/434772930f362145516dd60681134e7f0cf8115b
- https://github.com/apache/tomcat/commit/be8f330f83ceddaf3baeed57522e571572b6b99b
- https://github.com/apache/tomcat
- https://lists.apache.org/thread/p09775q0rd185m6zz98krg0fp45j8kr0
- https://lists.debian.org/debian-lts-announce/2025/07/msg00009.html
- http://www.openwall.com/lists/oss-security/2025/07/10/13
- https://www.suse.com/security/cve/CVE-2025-53506.html
- https://errata.rockylinux.org/RLSA-2025:14181
- https://security-tracker.debian.org/tracker/CVE-2025-53506
- https://access.redhat.com/errata/RHSA-2025:14177
- https://bugzilla.redhat.com/2373015
- https://bugzilla.redhat.com/2373018
- https://bugzilla.redhat.com/2373020
- https://bugzilla.redhat.com/2373309
- https://bugzilla.redhat.com/2379374
- https://bugzilla.redhat.com/2379382
- https://bugzilla.redhat.com/2379386
- https://errata.almalinux.org/8/ALSA-2025-14177.html
- https://errata.almalinux.org/9/ALSA-2025-14181.html
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.