High severity · published May 7, 2026
CVE-2026-42499
Quadratic string concatenation in consumePhrase in net/mail
7.5
CVSS
0.8%
EPSS
No
On KEV
Description
Pathological inputs could cause DoS through consumePhrase when parsing an email address according to RFC 5322.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 56% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
net/mail · Go standard library
before 1.25.10; 1.26.0-0 before 1.26.3 · source: vendor
GO
GO · Golang
before 1.25.10; 1.26.0 before 1.26.3 · source: NVD
CM
Cert Manager support for Red Hat OpenShift release 1.19 · Red Hat
All versions, or not specified · source: CISA
LS
Logging Subsystem for Red Hat OpenShift 6.4 · Red Hat
All versions, or not specified · source: CISA
LS
Logging Subsystem for Red Hat OpenShift 6.5 · Red Hat
All versions, or not specified · source: CISA
LF
Logging for Red Hat OpenShift 6 · Red Hat
All versions, or not specified · source: CISA
LF
Logging for Red Hat OpenShift 6.2 · Red Hat
All versions, or not specified · source: CISA
OA
OpenShift API for Data Protection 1.3 · Red Hat
All versions, or not specified · source: CISA
OA
OpenShift API for Data Protection 1.4 · Red Hat
All versions, or not specified · source: CISA
OA
OpenShift API for Data Protection 1.5 · Red Hat
All versions, or not specified · source: CISA
OA
OpenShift API for Data Protection 1.6 · Red Hat
All versions, or not specified · source: CISA
R1
RHEM 1.1 for RHEL 10 · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42499
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42499
Patch
https://go.dev/cl/771520
Issue Tracking
https://go.dev/issue/78987
Release Notes
https://groups.google.com/g/golang-announce/c/qcCIEXso47M
Vendor Advisory
https://pkg.go.dev/vuln/GO-2026-4977
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:17713
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:17714
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