CVE-2018-12088: S3QL before 2.27 mishandles checksumming, and consequently allows replay attacks in which an attacker who cont

Q: How do I fix CVE-2018-12088?

s3ql: upgrade to 2.27. Exact commands for each OS are on this page.

Q: Is CVE-2018-12088 being exploited?

CVE-2018-12088 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2018-12088 affect?

CVE-2018-12088 affects s3ql. Severity is high (CVSS 7.5). S3QL before 2.27 mishandles checksumming, and consequently allows replay attacks in which an attacker who controls the backend can present old versions of the filesystem metadata database as up-to-date, temporarily inject zero-valued bytes

Q: How urgent is CVE-2018-12088?

Priority 56/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2018-12088 is a high-severity flaw (CVSS 7.5) affecting s3ql. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

S3QL before 2.27 mishandles checksumming, and consequently allows replay attacks in which an attacker who controls the backend can present old versions of the filesystem metadata database as up-to-date, temporarily inject zero-valued bytes into files, or temporarily hide parts of files. This is related to the checksum_basic_mapping function.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.9% (top 21%)
CISA exploited list	No
Weakness	CWE-20
Published	2018-06-10
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: s3ql project

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

Am I affected?

Timeline

2018-06-10 23:29 UTCPublished CVE record published
2026-06-17 01:37 UTCUpdated Record last modified

s3ql project s3ql UPGRADE

Affected: < 2.27

Fixed in: 2.27

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy s3ql || rpm -q s3ql || s3ql --version

2. UPGRADE to 2.27 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade s3ql

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade s3ql

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2018-12088?

s3ql: upgrade to 2.27. Exact commands for each OS are on this page.

Is CVE-2018-12088 being exploited?

CVE-2018-12088 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-2018-12088 affect?

CVE-2018-12088 affects s3ql. Severity is high (CVSS 7.5). S3QL before 2.27 mishandles checksumming, and consequently allows replay attacks in which an attacker who controls the backend can present old versions of the filesystem metadata database as up-to-date, temporarily inject zero-valued bytes

How urgent is CVE-2018-12088?

Priority 56/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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