CVE-2026-73633: Uncontrolled resource consumption vulnerability in the JSON plugin of Apache Struts

This month

HIGH 7.5REMOTEWATCHLISTUPGRADE

CVE-2026-73633 is a high-severity flaw (CVSS 7.5) affecting struts. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Uncontrolled resource consumption vulnerability in the JSON plugin of Apache Struts. When an application is configured to populate actions from a JSON request body, the plugin reads that body into memory without bounding how much it will accept, so a single request can exhaust the heap and deny service to other users. The plugin's configurable JSON input length limit does not bound this read. The JSON plugin is an optional component; applications

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-400
Published	2026-08-14
Last modified	2026-08-18

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-08-18 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-14 14:16 UTCPublished CVE record published
2026-08-18 13:15 UTCUpdated Record last modified

apache struts UPGRADE

Affected: >= 2.1.8 and <= 2.3.37 · >= 2.5.0 and <= 2.5.33 · >= 6.0.0 and < 6.11.0 · >= 7.0.0 and < 7.3.0

Fixed in: 6.11.0, 7.3.0

Safe to downgrade to: a release before 2.1.8

1. Check installed version

apt-cache policy struts || rpm -q struts || struts --version

2. UPGRADE to 6.11.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade struts

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade struts

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.1.8 (Debian / Ubuntu)

apt-cache madison struts sudo apt install struts=<VERSION_BEFORE_2.1.8> sudo apt-mark hold struts

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list struts sudo dnf downgrade struts-<VERSION_BEFORE_2.1.8> sudo dnf versionlock add struts

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-73633?

struts: upgrade to 6.11.0, 7.3.0. Exact commands for each OS are on this page.

Is CVE-2026-73633 being exploited?

CVE-2026-73633 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-73633 affect?

CVE-2026-73633 affects struts. Severity is high (CVSS 7.5). Uncontrolled resource consumption vulnerability in the JSON plugin of Apache Struts. When an application is configured to populate actions from a JSON request body, the plugin reads that body into memory without bounding how much it will ac

How urgent is CVE-2026-73633?

Priority 49/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Apache Struts vulnerabilities

Related CVEs

CVE-2026-104714 HIGH 8.8 UPGRADE Concurrent execution using shared resource with improper synchronization ('race condition') vulnerability in A
CVE-2026-104713 MEDIUM 6.5 UPGRADE Allocation of resources without limits or throttling vulnerability in the Apache Struts REST plugin
CVE-2026-104712 HIGH 7.5 UPGRADE Asymmetric resource consumption (amplification) vulnerability in Apache Struts
CVE-2026-104711 CRITICAL 9.8 UPGRADE Improper neutralization of special elements used in an expression language statement ('Expression Language Inj
CVE-2026-73631 MEDIUM 4.3 DOWNGRADE Exposure of data element to wrong session vulnerability in the JSON plugin of Apache Struts

References

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