How severe is CVE-2017-12837?

CVE-2017-12837 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2017-12837 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-12837?

CVE-2017-12837 primarily affects Perl. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-12837?

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-2017-12837 published?

CVE-2017-12837 was published on 2017-09-19 and last updated on 2026-06-17.

CVE-2017-12837

CVE-2017-12837 is a high-severity vulnerability in Perl with a CVSS 3.x base score of 7.5. 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-119.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 6% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Perl
Published: 2017-09-19
Last modified: 2026-06-17

Description

Heap-based buffer overflow in the S_regatom function in regcomp.c in Perl 5 before 5.24.3-RC1 and 5.26.x before 5.26.1-RC1 allows remote attackers to cause a denial of service (out-of-bounds write) via a regular expression with a '\N{}' escape and the case-insensitive modifier.

Frequently asked questions

What is CVE-2017-12837?: Heap-based buffer overflow in the S_regatom function in regcomp.c in Perl 5 before 5.24.3-RC1 and 5.26.x before 5.26.1-RC1 allows remote attackers to cause a denial of service (out-of-bounds write) via a regular expression with a '\N{}' escape and the case-insensitive modifier.
How severe is CVE-2017-12837?: CVE-2017-12837 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2017-12837 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-12837?: CVE-2017-12837 primarily affects Perl. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-12837?: 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-2017-12837 published?: CVE-2017-12837 was published on 2017-09-19 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*
cpe:2.3:a:perl:perl:5.26.0:*:*:*:*:*:*:*

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CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

Browse all CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

182.93.50.90 (ipv4-addr)
103.165.139.145 (ipv4-addr)
121.40.151.192 (ipv4-addr)
40.83.182.122 (ipv4-addr)