How severe is CVE-2018-14340?

CVE-2018-14340 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-2018-14340 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-14340?

CVE-2018-14340 primarily affects Wireshark. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-14340?

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-2018-14340 published?

CVE-2018-14340 was published on 2018-07-19 and last updated on 2026-06-17.

CVE-2018-14340

CVE-2018-14340 is a high-severity vulnerability in Wireshark 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-125.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 3% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Wireshark
Published: 2018-07-19
Last modified: 2026-06-17

Description

In Wireshark 2.6.0 to 2.6.1, 2.4.0 to 2.4.7, and 2.2.0 to 2.2.15, dissectors that support zlib decompression could crash. This was addressed in epan/tvbuff_zlib.c by rejecting negative lengths to avoid a buffer over-read.

Frequently asked questions

What is CVE-2018-14340?: In Wireshark 2.6.0 to 2.6.1, 2.4.0 to 2.4.7, and 2.2.0 to 2.2.15, dissectors that support zlib decompression could crash. This was addressed in epan/tvbuff_zlib.c by rejecting negative lengths to avoid a buffer over-read.
How severe is CVE-2018-14340?: CVE-2018-14340 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-2018-14340 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-14340?: CVE-2018-14340 primarily affects Wireshark. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-14340?: 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-2018-14340 published?: CVE-2018-14340 was published on 2018-07-19 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:wireshark:wireshark:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

More vulnerabilities in Wireshark

CVE-2011-0444 — Critical (CVSS 10.0): Buffer overflow in the MAC-LTE dissector (epan/dissectors/packet-mac-lte.c) in Wireshark 1.2.0 through 1.2.13 and 1.4.0…
CVE-2010-2995 — Critical (CVSS 10.0): The SigComp Universal Decompressor Virtual Machine (UDVM) in Wireshark 0.10.8 through 1.0.14 and 1.2.0 through 1.2.9…
CVE-2010-2994 — Critical (CVSS 10.0): Stack-based buffer overflow in the ASN.1 BER dissector in Wireshark 0.10.13 through 1.0.14 and 1.2.0 through 1.2.9 has…
CVE-2009-1266 — Critical (CVSS 10.0): Unspecified vulnerability in Wireshark before 1.0.7 has unknown impact and attack vectors.
CVE-2009-1210 — Critical (CVSS 10.0): Format string vulnerability in the PROFINET/DCP (PN-DCP) dissector in Wireshark 1.0.6 and earlier allows remote…
CVE-2008-3146 — Critical (CVSS 10.0): Multiple buffer overflows in packet_ncp2222.inc in Wireshark (formerly Ethereal) 0.9.7 through 1.0.2 allow attackers to…

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Other CWE-125 (Out-of-bounds Read) vulnerabilities

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CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
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