CVE-2023-48307: Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform

Routine

LOW 3.5UPGRADE

CVE-2023-48307 is a low-severity flaw (CVSS 3.5) affecting mail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform. Starting in version 1.13.0 and prior to version 2.2.8 and 3.3.0, an attacker can use an unprotected endpoint in the Mail app to perform a SSRF attack. Nextcloud Mail app versions 2.2.8 and 3.3.0 contain a patch for this issue. As a workaround, disable the mail app.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	3.5 (Low)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.9% (top 41%)
CISA exploited list	No
Weakness	CWE-918
Published	2023-11-21
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: nextcloud

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

Am I affected?

Timeline

2023-11-21 23:15 UTCPublished CVE record published
2026-06-17 06:33 UTCUpdated Record last modified

nextcloud mail UPGRADE

Affected: >= 1.13.0 and < 2.2.8 · >= 3.0.0 and < 3.3.0

Fixed in: 2.2.8, 3.3.0

Safe to downgrade to: a release before 1.13.0

1. Check installed version

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

2. UPGRADE to 2.2.8 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mail

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 1.13.0 (Debian / Ubuntu)

apt-cache madison mail sudo apt install mail=<VERSION_BEFORE_1.13.0> sudo apt-mark hold mail

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

dnf --showduplicates list mail sudo dnf downgrade mail-<VERSION_BEFORE_1.13.0> sudo dnf versionlock add mail

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-2023-48307?

mail: upgrade to 2.2.8, 3.3.0. Exact commands for each OS are on this page.

Is CVE-2023-48307 being exploited?

CVE-2023-48307 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-2023-48307 affect?

CVE-2023-48307 affects mail. Severity is low (CVSS 3.5). Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform. Starting in version 1.13.0 and prior to version 2.2.8 and 3.3.0, an attacker can use an unprotected endpoint in the Mail app to perform a SSRF attack. Nextcl

How urgent is CVE-2023-48307?

Priority 27/100. No elevated risk signals yet.

Software pages

Nextcloud vulnerabilities

Related CVEs

CVE-2025-66514 LOW 3.5 UPGRADE Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform
CVE-2024-52509 LOW 3.5 UPGRADE Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform
CVE-2024-52508 HIGH 8.2 UPGRADE Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform
CVE-2023-45660 MEDIUM 4.3 UPGRADE Nextcloud mail is an email app for the Nextcloud home server platform
CVE-2023-33184 LOW 3.5 UPGRADE Nextcloud Mail is a mail app in Nextcloud

References

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