CVE-2018-17942: The convert_to_decimal function in vasnprintf.c in Gnulib before 2018-09-23 has a heap-based buffer overflow b

Q: How do I fix CVE-2018-17942?

gnulib: upgrade to 2018-09-23. Exact commands for each OS are on this page.

Q: Is CVE-2018-17942 being exploited?

CVE-2018-17942 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-2018-17942 affect?

CVE-2018-17942 affects gnulib. Severity is high (CVSS 8.8). The convert_to_decimal function in vasnprintf.c in Gnulib before 2018-09-23 has a heap-based buffer overflow because memory is not allocated for a trailing '\0' character during %f processing.

Q: How urgent is CVE-2018-17942?

Priority 57/100. High severity; Public exploit reference

This month

HIGH 8.8UPGRADE

CVE-2018-17942 is a high-severity flaw (CVSS 8.8) affecting gnulib. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The convert_to_decimal function in vasnprintf.c in Gnulib before 2018-09-23 has a heap-based buffer overflow because memory is not allocated for a trailing '\0' character during %f processing.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	2.5% (top 15%)
CISA exploited list	No
Weakness	CWE-787
Published	2018-10-03
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: gnu

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

Am I affected?

Timeline

2018-10-03 08:29 UTCPublished CVE record published
2026-06-17 01:46 UTCUpdated Record last modified

gnu gnulib UPGRADE

Affected: < 2018-09-23

Fixed in: 2018-09-23

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2018-09-23 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade gnulib

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-2018-17942?

gnulib: upgrade to 2018-09-23. Exact commands for each OS are on this page.

Is CVE-2018-17942 being exploited?

CVE-2018-17942 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-2018-17942 affect?

CVE-2018-17942 affects gnulib. Severity is high (CVSS 8.8). The convert_to_decimal function in vasnprintf.c in Gnulib before 2018-09-23 has a heap-based buffer overflow because memory is not allocated for a trailing '\0' character during %f processing.

How urgent is CVE-2018-17942?

Priority 57/100. High severity; Public exploit reference

Related CVEs

CVE-2017-7476 CRITICAL 9.8 UPGRADE Gnulib before 2017-04-26 has a heap-based buffer overflow with the TZ environment variable

References

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