CVE-2026-49939: In Apache James server prior version 3.9.1 improper Access Control List processing is exposed by the JMAP prot

Routine

HIGH n/aWATCHLISTUPGRADE

CVE-2026-49939 is a high-severity flaw (CVSS n/a) affecting apache james. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Apache James server prior version 3.9.1 improper Access Control List processing is exposed by the JMAP protocol which do not account for negative rules positionned by IMAP protocol. This results in users being able to administer folders in JMAP despite having being explicitly denied the right to do so in IMAP. Users are recommended to upgrade to version 3.9.1 which fixes this issue.

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	n/a (High)
EPSS exploit chance	n/a
CISA exploited list	No
Weakness	CWE-284
Published	2026-11-06
Last modified	2026-11-06

Publisher (CNA): apache · Vendor: apache software foundation · Source: CVE Program record (NVD analysis pending)

Last updated 2026-11-06 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-11-06 11:40 UTCPublished CVE record published
2026-11-06 11:40 UTCUpdated Record last modified

apache software foundation apache james UPGRADE

Affected: >= 3.9.0 and < 3.9.1

Fixed in: 3.9.1

Safe to downgrade to: a release before 3.9.0

1. Check installed version

apt-cache policy apache-james || rpm -q apache-james || apache-james --version

2. UPGRADE to 3.9.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade apache-james

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade apache-james

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 3.9.0 (Debian / Ubuntu)

apt-cache madison apache-james sudo apt install apache-james=<VERSION_BEFORE_3.9.0> sudo apt-mark hold apache-james

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

dnf --showduplicates list apache-james sudo dnf downgrade apache-james-<VERSION_BEFORE_3.9.0> sudo dnf versionlock add apache-james

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-2026-49939?

apache james: upgrade to 3.9.1. Exact commands for each OS are on this page.

Is CVE-2026-49939 being exploited?

CVE-2026-49939 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-2026-49939 affect?

CVE-2026-49939 affects apache james. Severity is high (CVSS n/a). In Apache James server prior version 3.9.1 improper Access Control List processing is exposed by the JMAP protocol which do not account for negative rules positionned by IMAP protocol. This results in users being able to administer folders

How urgent is CVE-2026-49939?

Priority 5/100. On your watchlist

Related CVEs

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CVE-2025-66621 HIGH n/a UPGRADE Apache James SASL OAuthBearer/XOAUTH2 prior versions 3.9.1 fails to validate correctly AUD claim of JWT payloa

References

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