CVE-2026-42788
📛 CVE Title
HTTP/2 frame size limit checked after body is buffered in bandit
Description
Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated memory exhaustion via oversized HTTP/2 frames. 'Elixir.Bandit.HTTP2.Frame':deserialize/2 in lib/bandit/http2/frame.ex checks the SETTINGS_MAX_FRAME_SIZE limit only after pattern-matching payload::binary-size(length), which requires the entire frame body to be present in memory before either the accept or reject clause can fire. A peer that announces a frame length up to the 24-bit maximum (~16 MiB) causes the server to buffer that entire body before the size guard is evaluated, regardless of the max_frame_size negotiated during the HTTP/2 handshake (default 16 KiB per RFC 9113). An unauthenticated attacker holding many concurrent connections can force the server to buffer far more memory than the negotiated frame size limit should permit, leading to memory pressure and potential denial of service. This issue affects bandit: from 0.3.6 before 1.11.0.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- EEF
- CVSS severity
- MEDIUM
- CVSS score
- 6.9 / 10
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N- Effective score
- 6.9 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-770 - Reserved
- 2026-04-29
- Published
- 2026-05-01 22:34 UTC
- Last updated
- 2026-05-04 19:11 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/42xxx/CVE-2026-42788.json
- Linked Threat
- CVE-2026-42788 — CVE-2026-42788
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
- 2026-05-01 21:16:17 UTC
- NVD last modified
- 2026-05-05 19:37:28 UTC
- EPSS score
- 0.0002 (probability of exploitation in next 30 days)
- EPSS percentile
- 6.42% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 09:19 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-2026-26716 - Assigner
- EEF
- Published
- May 1, 2026, 8:34:11 PM
- Updated
- May 27, 2026, 3:40:29 PM
- EUVD base score (CVSS 4.0)
-
6.9 / 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - EUVD-reported EPSS
- 0.0200
- Vendors
- mtrudel
- Products
-
bandit (0.3.6 <1.11.0)bandit (f00dd69a5b2a4863be585907acd853c4ffd41399 <1.11.0)bandit (f00dd69a5b2a4863be585907acd853c4ffd41399 <1e8e55966da9129016b73d32f0e1df4630e3b463)
ENISA description: Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated memory exhaustion via oversized HTTP/2 frames. 'Elixir.Bandit.HTTP2.Frame':deserialize/2 in lib/bandit/http2/frame.ex checks the SETTINGS_MAX_FRAME_SIZE limit only after pattern-matching payload::binary-size(length), which requires the entire frame body to be present in memory before either the accept or reject clause can fire. A peer that announces a frame length up to the 24-bit maximum (~16 MiB) causes the server to buffer that entire body before the size guard is evaluated, regardless of the max_frame_size negotiated during the HTTP/2 handshake (default 16 KiB per RFC 9113). An unauthenticated attacker holding many concurrent connections can force the server to buffer far more memory than the negotiated frame size limit should permit, leading to memory pressure and potential denial of service. This issue affects bandit: from 0.3.6 before 1.11.0.
Affected products (2)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| mtrudel | bandit |
0.3.6 (affected)
|
— |
| mtrudel | bandit |
f00dd69a5b2a4863be585907acd853c4ffd41399 (affected)
|
— |
Vendor references (4)
References embedded in the original CVE record by the assigning CNA.
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.
- https://cna.erlef.org/cves/CVE-2026-42788.html tenable:cna.erlef.org
- https://github.com/mtrudel/bandit/commit/1e8e55966da9129016b73d32f0e1df4630e3b463 tenable:github.com
- https://github.com/mtrudel/bandit/security/advisories/GHSA-q6v9-r226-v65f tenable:github.com
- https://nvd.nist.gov/vuln/detail/CVE-2026-42788 tenable:nvd.nist.gov
- https://osv.dev/vulnerability/EEF-CVE-2026-42788 tenable:osv.dev
- https://www.cve.org/CVERecord?id=CVE-2026-42788 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (5)
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://cna.erlef.org/cves/CVE-2026-42788.html 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://github.com/mtrudel/bandit/commit/1e8e55966da9129016b73d32f0e1df4630e3b463 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://github.com/mtrudel/bandit/security/advisories/GHSA-q6v9-r226-v65f 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://github.com/mtrudel/bandit/security/advisories/GHSA-q6v9-r226-v65f 134c704f-9b21-4f2e-91b3-4a467353bcc0
- https://osv.dev/vulnerability/EEF-CVE-2026-42788 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Remediations (18)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:blog.qualys.com
With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.
2026-05-23 20:23 UTC -
web:cybersecuritynews.com
Microsoft released its March 2026 Patch Tuesday security update on March 10, 2026 , addressing 78 vulnerabilities across Windows, Microsoft Office, Azure, SQL Server, and .NET. The update includes one actively exploited zero-day vulnerability and multiple Critical-rated flaws demanding immediate attention from security teams. The most urgent fix this month is CVE - 2026 -21262, the sole zero-day ...
2026-05-23 20:23 UTC -
web:heimdalsecurity.com
Explore six essential patch management best practices for 2026 to keep your systems secure, up to date, and protected from vulnerabilities.
2026-05-23 20:23 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 20:23 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 20:23 UTC -
web:support.sap.com
SAP security Patch Day Bulletin
2026-05-23 20:23 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's February 2026 Patch Tuesday with security updates for 58 flaws, including 6 actively exploited and three publicly disclosed zero-day vulnerabilities.
2026-05-23 20:23 UTC -
web:www.computerworld.com
Each month, the team at Readiness analyzes the latest Patch Tuesday updates from Microsoft and provides detailed, actionable testing guidance. The company's Patch Tuesday release for February ...
2026-05-23 20:23 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.
2026-05-23 20:23 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-05-23 20:23 UTC -
web:blog.qualys.com
Microsoft and Adobe Patch Tuesday, April 2026 Security Update Review Posted in Patch Tuesday, Vulnerabilities and Threat Research 7 Diksha Ojha March 11, 2026 - 8 min read
2026-06-03 07:49 UTC -
web:cybersecuritynews.com
Microsoft's May 2026 Patch Tuesday lands with a heavy enterprise focus, fixing 120 vulnerabilities across Windows, Office, Azure, developer tools, and Microsoft 365 apps, including 29 remote code execution (RCE) flaws rated Critical.
2026-06-03 07:49 UTC -
web:msrc.microsoft.com
The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.
2026-06-03 07:49 UTC -
web:nvd.nist.gov
Information Technology Laboratory National Vulnerability Database Vulnerabilities
2026-06-03 07:49 UTC -
web:windowsforum.com
The mitigation name administrators should verify for CVE - 2026 -42897 is M2. Exchange Server 2016, Exchange Server 2019, and Exchange Server Subscription Edition are affected at any update level, while Exchange Online is not affected.
2026-06-03 07:49 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's March 2026 Patch Tuesday with security updates for 79 flaws, including 2 publicly disclosed zero-day vulnerabilities.
2026-06-03 07:49 UTC -
web:www.crowdstrike.com
Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.
2026-06-03 07:49 UTC -
web:www.securityweek.com
Oracle on Tuesday announced the release of 481 new security patches as part of its April 2026 Critical Patch Update (CPU). Across the 28 product families that received security updates, more than 300 patches address vulnerabilities that are remotely exploitable without authentication. Roughly three dozen fixes resolve critical-severity security defects. There appear to be approximately 450 ...
2026-06-03 07:49 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-42788.json.
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