CVE-2026-73631: Exposure of data element to wrong session vulnerability in the JSON plugin of Apache Struts

Routine

MEDIUM 4.3WATCHLISTDOWNGRADE

CVE-2026-73631 is a medium-severity flaw (CVSS 4.3) affecting struts. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Exposure of data element to wrong session vulnerability in the JSON plugin of Apache Struts. Per-request parsing state could be shared across concurrent requests, allowing data associated with one request to become observable in another, and configured parsing limits not to be enforced as intended. Populating actions from a JSON request body is not enabled by default; applications that do not use the JSON plugin are not affected. This issue affe

Why this priority

On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 69%)
CISA exploited list	No
Weakness	CWE-567
Published	2026-08-15
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

2026-08-15 11:16 UTCPublished CVE record published
2026-08-18 17:47 UTCUpdated Record last modified

apache struts DOWNGRADE

Affected: 7.2.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.2.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 7.2.1 (Debian / Ubuntu)

apt-cache madison struts sudo apt install struts=<VERSION_BEFORE_7.2.1> sudo apt-mark hold struts

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list struts sudo dnf downgrade struts-<VERSION_BEFORE_7.2.1> 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-2026-73631?

struts: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-73631 being exploited?

CVE-2026-73631 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-2026-73631 affect?

CVE-2026-73631 affects struts. Severity is medium (CVSS 4.3). Exposure of data element to wrong session vulnerability in the JSON plugin of Apache Struts. Per-request parsing state could be shared across concurrent requests, allowing data associated with one request to become observable in another, an

How urgent is CVE-2026-73631?

Priority 28/100. 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-2026-73632 MEDIUM 4.3 DOWNGRADE Exposure of data element to wrong session vulnerability in the JSON plugin of Apache Struts

References

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