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Fencer Vulns
medium 5.5

CVE-2018-21232 json

re2c before 2.0 has uncontrolled recursion that causes stack consumption in find_fixed_tags.

published 2020-04-29 6 y ago modified 2026-06-17 4 mo ago also EUVD-2018-13750

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 73%
public exploits
0
none known

Summary

re2c before 2.0 has uncontrolled recursion that causes stack consumption in find_fixed_tags.

Patch / fix

  • re2c re2c 2.0
  • re2c Debian 14, Debian 13 3.1-1

debian advisories DEBIAN-CVE-2018-21232

  • re2c SLE Module for Basesystem 15 SP5, SLE Module for Basesystem 15 SP4, openSUSE Leap 15.5 +3 more 1.0.3-150000.3.3.1

suse advisories SUSE-SU-2023:3353-1

  • re2c CBL-Mariner 2.0 2.0-1

azure linux advisories AZL-7337

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-21232 updated cvss 5.5

re2c: uncontrolled recursion that causes stack consumption in find_fixed_tags

  • Red Hat Enterprise Linux 8 re2c
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.47% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/skvadrik/re2c/issues/219 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.