CVE-2026-40986: Spring Web Flow's JavaScript RemotingHandler renders the body of an error response as HTML even when the respo

Routine

MEDIUM 4.8UPGRADE

CVE-2026-40986 is a medium-severity flaw (CVSS 4.8) affecting spring web flow. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Spring Web Flow's JavaScript RemotingHandler renders the body of an error response as HTML even when the response is not "text/html", which can result in a scripting attack in the user's browser if the error response from the server contains error details with input reflected from an attacker. Affected versions: Spring Web Flow 4.0.0; 3.0.0 through 3.0.1; 2.5.0 through 2.5.1.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.8 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.2% (top 89%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-06-11
Last modified	2026-09-04

Publisher (CNA): VMware · Vendor: broadcom

Last updated 2026-09-04 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-11 07:16 UTCPublished CVE record published
2026-09-04 18:11 UTCUpdated Record last modified

broadcom spring web flow UPGRADE

Affected: < 2.5.2 · >= 3.0.0 and < 3.0.1.1 · 4.0.0

Fixed in: 2.5.2, 3.0.1.1

Safe to downgrade to: a release before 3.0.0

1. Check installed version

apt-cache policy spring-web-flow || rpm -q spring-web-flow || spring-web-flow --version

2. UPGRADE to 2.5.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade spring-web-flow

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade spring-web-flow

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 3.0.0 (Debian / Ubuntu)

apt-cache madison spring-web-flow sudo apt install spring-web-flow=<VERSION_BEFORE_3.0.0> sudo apt-mark hold spring-web-flow

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

dnf --showduplicates list spring-web-flow sudo dnf downgrade spring-web-flow-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add spring-web-flow

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-2026-40986?

spring web flow: upgrade to 2.5.2, 3.0.1.1. Exact commands for each OS are on this page.

Is CVE-2026-40986 being exploited?

CVE-2026-40986 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-2026-40986 affect?

CVE-2026-40986 affects spring web flow. Severity is medium (CVSS 4.8). Spring Web Flow's JavaScript RemotingHandler renders the body of an error response as HTML even when the response is not "text/html", which can result in a scripting attack in the user's browser if the error response from the server contain

How urgent is CVE-2026-40986?

Priority 19/100. No elevated risk signals yet.

Related CVEs

CVE-2026-40985 MEDIUM 6.4 UPGRADE Applications that configure the WebFlowELExpressionParser are vulnerable to the use of malicious Unified EL ex

References

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