CVE-2026-66296: Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in lud oaskit allows reflected

Routine

MEDIUM 6.1UPGRADE

CVE-2026-66296 is a medium-severity flaw (CVSS 6.1) affecting oaskit. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in lud oaskit allows reflected cross-site scripting via the default HTML error handler. Oaskit.ErrorHandler.Default.format_reason/4 and Oaskit.ErrorHandler.Default.reason_to_html/1 in lib/oaskit/error_handler/default.ex render request-validation failures as an HTML page whenever the request's Accept header contains html, interpolating request-controlled strings into

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 71%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-08-03
Last modified	2026-10-23

Publisher (CNA): EEF · Vendor: lud

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-03 20:17 UTCPublished CVE record published
2026-10-23 21:10 UTCUpdated Record last modified

lud oaskit UPGRADE

Affected: >= 0.1.0 and < 0.14.1

Fixed in: 0.14.1

Safe to downgrade to: a release before 0.1.0

1. Check installed version

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

2. UPGRADE to 0.14.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade oaskit

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 0.1.0 (Debian / Ubuntu)

apt-cache madison oaskit sudo apt install oaskit=<VERSION_BEFORE_0.1.0> sudo apt-mark hold oaskit

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

dnf --showduplicates list oaskit sudo dnf downgrade oaskit-<VERSION_BEFORE_0.1.0> sudo dnf versionlock add oaskit

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.

Exact fixes by distribution

Fedora 46 · sugar-calculator · FIXED · 47-14.fc46 · FEDORA-2026-38eeb9e279 · source

sudo dnf upgrade --advisory=FEDORA-2026-38eeb9e279

Fedora ELN · selinux-policy · FIXED · 45.23-1.eln159 · FEDORA-2026-3668c969a2 · source

sudo dnf upgrade --advisory=FEDORA-2026-3668c969a2

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/lud/oaskit/security/advisories/GHSA-h7xw-x8wr-xpcc

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-2026-66296?

oaskit: upgrade to 0.14.1. Exact commands for each OS are on this page.

Is CVE-2026-66296 being exploited?

CVE-2026-66296 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-2026-66296 affect?

CVE-2026-66296 affects oaskit. Severity is medium (CVSS 6.1). Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in lud oaskit allows reflected cross-site scripting via the default HTML error handler. Oaskit.ErrorHandler.Default.format_reason/4 and Oaskit.ErrorHandler.Def

How urgent is CVE-2026-66296?

Priority 34/100. Public exploit reference

References

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