CVE-2021-26903: LMA ISIDA Retriever 5.2 is vulnerable to XSS via query['text'].

Routine

MEDIUM 6.1DOWNGRADE

CVE-2021-26903 is a medium-severity flaw (CVSS 6.1) affecting retriever. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

LMA ISIDA Retriever 5.2 is vulnerable to XSS via query['text'].

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.0% (top 38%)
CISA exploited list	No
Weakness	CWE-79
Published	2021-02-26
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: isida

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-02-26 15:15 UTCPublished CVE record published
2026-06-17 03:43 UTCUpdated Record last modified

isida retriever DOWNGRADE

Affected: 5.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.2

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 5.2 (Debian / Ubuntu)

apt-cache madison retriever sudo apt install retriever=<VERSION_BEFORE_5.2> sudo apt-mark hold retriever

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

dnf --showduplicates list retriever sudo dnf downgrade retriever-<VERSION_BEFORE_5.2> sudo dnf versionlock add retriever

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-2021-26903?

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

Is CVE-2021-26903 being exploited?

CVE-2021-26903 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-2021-26903 affect?

CVE-2021-26903 affects retriever. Severity is medium (CVSS 6.1). LMA ISIDA Retriever 5.2 is vulnerable to XSS via query['text'].

How urgent is CVE-2021-26903?

Priority 37/100. No elevated risk signals yet.

Related CVEs

CVE-2021-26904 CRITICAL 9.8 DOWNGRADE LMA ISIDA Retriever 5.2 allows SQL Injection.

References

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