CVE-2020-11958
CVE-2020-11958 is a high-severity vulnerability in Re2c with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.
Key facts
- Severity: High (CVSS 3.x base score 7.8)
- CVSS v2: 6.8
- EPSS exploit prediction: 2% (74th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-787
- Affected product: Re2c
- Published:
- Last modified:
Description
re2c 1.3 has a heap-based buffer overflow in Scanner::fill in parse/scanner.cc via a long lexeme.
Frequently asked questions
- What is CVE-2020-11958?
- re2c 1.3 has a heap-based buffer overflow in Scanner::fill in parse/scanner.cc via a long lexeme.
- How severe is CVE-2020-11958?
- CVE-2020-11958 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2020-11958 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2020-11958?
- CVE-2020-11958 primarily affects Re2c. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2020-11958?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2020-11958 published?
- CVE-2020-11958 was published on 2020-04-21 and last updated on 2026-06-17.
References
- http://www.openwall.com/lists/oss-security/2020/04/21/1
- https://blogs.gentoo.org/ago/2020/04/19/re2c-heap-overflow-in-scannerfill-scanner-cc/
- https://github.com/skvadrik/re2c/commit/c4603ba5ce229db83a2a4fb93e6d4b4e3ec3776a
- https://security.gentoo.org/glsa/202007-28
- https://usn.ubuntu.com/4338-1/
- https://usn.ubuntu.com/4338-2/
- https://www.openwall.com/lists/oss-security/2020/04/19/1
Affected products (3)
- cpe:2.3:a:re2c:re2c:1.3:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
More vulnerabilities in Re2c
- CVE-2022-23901 — Critical (CVSS 9.8): A stack overflow re2c 2.2 exists due to infinite recursion issues in src/dfa/dead_rules.cc.
- CVE-2018-21232 — Medium (CVSS 5.5): re2c before 2.0 has uncontrolled recursion that causes stack consumption in find_fixed_tags.
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