CVE-2026-42499
📛 CVE Title
Quadratic string concatenation in consumePhrase in net/mail
Description
Pathological inputs could cause DoS through consumePhrase when parsing an email address according to RFC 5322.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- Go
- CVSS severity
- high
- CVSS score
- 7.5 / 10
- CVSS vector
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Effective score
- 7.5 / 10 HIGH source: CNA overview
- MSRC score
- 7.5 / 10 HIGH MS rating: Important
- CWE(s)
-
CWE-407: Inefficient Algorithmic Complexity - Reserved
- 2026-04-28
- Published
- 2026-05-07 21:41 UTC
- Last updated
- 2026-05-08 23:29 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/42xxx/CVE-2026-42499.json
- Linked Threat
- CVE-2026-42499 — CVE-2026-42499
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-07 20:16:44 UTC
- NVD last modified
- 2026-05-13 16:59:17 UTC
- NVD CVSS v3.1
- 7.5 / 10 HIGH source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 3.6 / 10
- EPSS score
- 0.0002 (probability of exploitation in next 30 days)
- EPSS percentile
- 6.41% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 09:24 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-28432 - Assigner
- Go
- Published
- May 7, 2026, 7:41:18 PM
- Updated
- May 8, 2026, 9:29:59 PM
- EUVD base score (CVSS 3.1)
-
7.5 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EUVD-reported EPSS
- 0.0200
- Vendors
- Go standard library
- Products
-
net/mail (1.26.0-0 <1.26.3)net/mail (0 <1.25.10)
ENISA description: Pathological inputs could cause DoS through consumePhrase when parsing an email address according to RFC 5322.
Microsoft Security Response Center MSRC
Microsoft's vendor-authoritative record from the Security Update Guide — its own CVSS score, impact, severity rating, exploit assessment, and KB-article fixes. Refreshed 2026-08-12 01:09 UTC (source: CVRF).
- MS severity
- Important
- MS CVSS base score
- 7.5 / 10 (temporal 7.5)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Release
- 2026-May
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| Go standard library | net/mail |
0 (affected),
1.26.0-0 (affected)
|
— |
Affected products — CPE 2.3 (1) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
Vendor references (4)
References embedded in the original CVE record by the assigning CNA.
MITRE references (4) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
Web references (7)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- MSRC update guide: CVE-2026-42499 msrc
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-28432 rapid7:euvd.enisa.europa.eu
- https://attackerkb.com/topics/CVE-2026-42499 rapid7:attackerkb.com
- https://security.alpinelinux.org/vuln/CVE-2026-42499 rapid7:security.alpinelinux.org
- https://www.first.org/epss/ tenable:www.first.org
- https://www.cve.org/CVERecord?id=CVE-2026-42499 tenable:www.cve.org
- https://nvd.nist.gov/vuln/detail/CVE-2026-42499 tenable:nvd.nist.gov
NVD-tagged references (4)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://go.dev/cl/771520 security@golang.org Patch
- https://go.dev/issue/78987 security@golang.org Issue Tracking
- https://groups.google.com/g/golang-announce/c/qcCIEXso47M security@golang.org Release Notes
- https://pkg.go.dev/vuln/GO-2026-4977 security@golang.org Vendor Advisory
Remediations (18)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:cyberinsider.com
Microsoft has released the May 2026 Patch Tuesday updates for Windows 11, fixing 97 security vulnerabilities across the Windows ecosystem. This month's updates include fixes spanning Windows components, Microsoft Office, Azure services, SQL Server, SharePoint, Hyper-V, .NET, and multiple cloud platforms.
2026-05-23 21:08 UTC -
web:cyberpress.org
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .
2026-05-23 21:08 UTC -
web:krebsonsecurity.com
Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.
2026-05-23 21:08 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-23 21:08 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-23 21:08 UTC -
web:thecyberexpress.com
Microsoft confirms active exploitation of CVE - 2026 -41091 and CVE - 2026 -45498 in Defender, with CVSS-rated risks, KEV listing, and urgent patches issued.
2026-05-23 21:08 UTC -
web:www.cisecurity.org
<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...
2026-05-23 21:08 UTC -
web:www.csoonline.com
Microsoft released emergency fixes for two zero-day vulnerabilities in the malware protection components of Microsoft Defender. The flaws allow local attackers to gain system-level privileges or ...
2026-05-23 21:08 UTC -
web:www.forbes.com
Microsoft has confirmed an emergency security update as CISA warns that two new Defender zero-days are being exploited by attackers.
2026-05-23 21:08 UTC -
web:www.techradar.com
CISA confirms two bugs being actively exploited in the wild, as Microsoft releases patches.
2026-05-23 21:08 UTC -
web:aws.amazon.com
Read our latest security bulletins here. We investigate all reported security vulnerabilities affecting Amazon and AWS services, software, and products. To support our customers in prioritizing and addressing known issues, we publish Security Bulletins filtered by the following criteria: Important Bulletins require attention (e.g. impact assessment, mitigation ) Informational Bulletins are ...
2026-05-26 02:46 UTC -
web:community.ui.com
Published: May 21, 2026 Updated: May 22, 2026 Version: 1.1 Revision: 1.1 Summary 1 of 5 A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection. Affected Products: UniFi OS Server (Version 5.0.6 and earlier) Mitigation : Update your UniFi OS Server to Version 5.0.8 or later ...
2026-05-26 02:46 UTC -
web:cvevault.com
CVE Vault - Search and explore Common Vulnerabilities and Exposures ( CVE ) database. Find security vulnerabilities by CVE ID, vendor, severity, and year. Stay secure with comprehensive CVE information.
2026-05-26 02:46 UTC -
web:source.android.com
Android partners are encouraged to fix all issues in this bulletin and use the latest security patch level. Devices that use the 2025-04-01 security patch level must include all issues associated with that security patch level, as well as fixes for all issues reported in previous security bulletins.
2026-05-26 02:46 UTC -
web:www.cisa.gov
For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild. Organizations should use the KEV catalog as an input to their vulnerability management prioritization framework.
2026-05-26 02:46 UTC -
web:www.esri.com
Key highlights Portal for ArcGIS Security 2026 Update 1 Patch Portal for ArcGIS 11.4, 11.5, and 12.0 require a security patch US CISA recommends applying Critical Security patches within 15 days Patch /update resets potentially over-scoped developer credentials Check if your applications/scripts using developer credentials are fully operational after update
2026-05-26 02:46 UTC -
web:www.nist.gov
NIST maintains the National Vulnerability Database (NVD), a repository of information on software and hardware flaws that can compromise computer security. This is a key piece of the nation's cybersecurity infrastructure.
2026-05-26 02:46 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-26 02:46 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-42499.json.
{
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{
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
}
},
{
"other": {
"content": {
"id": "CVE-2026-42499",
"options": [
{
"Exploitation": "none"
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{
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},
{
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}
],
"role": "CISA Coordinator",
"timestamp": "2026-05-08T16:55:28.873015Z",
"version": "2.0.3"
},
"type": "ssvc"
}
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"providerMetadata": {
"dateUpdated": "2026-05-08T21:29:59.662Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://pkg.go.dev",
"defaultStatus": "unaffected",
"packageName": "net/mail",
"product": "net/mail",
"programRoutines": [
{
"name": "addrParser.consumePhrase"
},
{
"name": "AddressParser.Parse"
},
{
"name": "AddressParser.ParseList"
},
{
"name": "Header.AddressList"
},
{
"name": "ParseAddress"
},
{
"name": "ParseAddressList"
}
],
"vendor": "Go standard library",
"versions": [
{
"lessThan": "1.25.10",
"status": "affected",
"version": "0",
"versionType": "semver"
},
{
"lessThan": "1.26.3",
"status": "affected",
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}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Pathological inputs could cause DoS through consumePhrase when parsing an email address according to RFC 5322."
}
],
"problemTypes": [
{
"descriptions": [
{
"description": "CWE-407: Inefficient Algorithmic Complexity",
"lang": "en"
}
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}
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"providerMetadata": {
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"references": [
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"url": "https://go.dev/issue/78987"
},
{
"url": "https://go.dev/cl/771520"
},
{
"url": "https://groups.google.com/g/golang-announce/c/qcCIEXso47M"
},
{
"url": "https://pkg.go.dev/vuln/GO-2026-4977"
}
],
"title": "Quadratic string concatenation in consumePhrase in net/mail"
}
},
"cveMetadata": {
"assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
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"datePublished": "2026-05-07T19:41:18.615Z",
"dateReserved": "2026-04-28T00:21:12.791Z",
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