# Require patch-format support before applying a partial resource change > Use RFC 5789 — PATCH Method for HTTP to review this narrow operational decision without extending the source beyond its stated scope. - Canonical URL: https://update.dsesecurity.com/updates/require-patch-format-support-before-applying-a-partial-resource-change/ - Publisher: Detection Systems & Engineering (DSE Security) - Author: DSE Security Editorial Team - Published: 2026-08-27T12:15:49+00:00 - Modified: 2026-08-27T12:53:58+00:00 - Last reviewed by DSE: 2026-08-26 - Resource type: Checklist - DSE priority: Advisory - Topics: Cybersecurity, Networks & Infrastructure - Reading time: 3 minutes ## What you need to know Use RFC 5789 — PATCH Method for HTTP to review this narrow operational decision without extending the source beyond its stated scope. ## Potentially affected Teams, systems, services, or facilities within the stated scope of RFC 5789 — PATCH Method for HTTP ## DSE recommendation Compare the observed state with the cited official source, document applicability and exceptions, and test any approved change with rollback safeguards. ## Article Treat this document as a focused evidence review: Require patch-format support before applying a partial resource change. Only the official source and traced locations below supply facts. Confirm applicability before acting. ## Source fact: The official [RFC 5789 — PATCH Method for HTTP](https://www.rfc-editor.org/rfc/rfc5789.html) from RFC Editor / Internet Engineering Task Force supports the following bounded statements: - A server supporting PATCH should advertise each accepted patch-document media type in Accept-Patch; the header’s presence also indicates that PATCH is allowed for that resource. The research record locates this support at Section 3.1 (The Accept-Patch Header). - When a patch format depends on a known base, the client SHOULD make PATCH conditional so it fails if the resource changed, such as by using a strong ETag in If-Match. The research record locates this support at Section 2 (The PATCH Method), collision handling. - The server MUST apply the entire patch atomically, never expose a partially modified representation, and apply none of the changes if the complete patch cannot succeed. The research record locates this support at Section 2 (The PATCH Method), atomicity requirements. Keep the evidence boundary at these traced claims. They support a review of clients, origin services, intermediaries, caches, proxies, gateways, protocol versions, and security-policy enforcement points; they do not support conclusions outside the source’s stated conditions. ## What the source does not establish This RFC evidence supports only the named web or transport decision; it does not prove browser, intermediary, library, or service compatibility. It does not establish a deployment’s current state, authorize a production change, prove compliance, or show that DNS, certificates, identity providers, time, content delivery, network paths, and application ownership are healthy. Documented options are review inputs, not universal mandates. ## Applicability questions - For source statement 1 at Section 3.1 (The Accept-Patch Header), which observable configuration, record, or test can confirm applicability here? - For source statement 2 at Section 2 (The PATCH Method), collision handling, which observable configuration, record, or test can confirm applicability here? - For source statement 3 at Section 2 (The PATCH Method), atomicity requirements, which observable configuration, record, or test can confirm applicability here? - What inventory proves which parts of clients, origin services, intermediaries, caches, proxies, gateways, protocol versions, and security-policy enforcement points are in and out of scope? - Which condition in DNS, certificates, identity providers, time, content delivery, network paths, and application ownership must be healthy before evidence is trustworthy? - What result would disprove the working assumption and return the issue to the owner? ## DSE recommendation: DSE recommends using the cited source as the evidence anchor for this decision. Anchor the review in the cited section and keep observation separate from interpretation. Record the source location, examined part of clients, origin services, intermediaries, caches, proxies, gateways, protocol versions, and security-policy enforcement points, observed and expected states, owner, and reason for deviation. If the review warrants change, use a bounded implementation with prerequisites, test population, monitoring, abort criteria, and a rehearsed reversal. Sequence checks for DNS, certificates, identity providers, time, content delivery, network paths, and application ownership and sanitize protected material before retention. ## Verification and evidence A reviewer should be able to retrace the decision from Section 3.1 (The Accept-Patch Header); Section 2 (The PATCH Method), collision handling; Section 2 (The PATCH Method), atomicity requirements through request and response captures, negotiated protocol details, headers, cache behavior, certificate state, and server or proxy logs. Record what was collected, where, when, by whom, and which system or role it represents. Record the decision even when no change is made, including uncertainty and the next trigger. Use safe testing conditions for disruptive work, preserve rollback proof, and revisit the conclusion after relevant platform, dependency, vendor, or ownership changes. ## Official references - [RFC 5789 — PATCH Method for HTTP](https://www.rfc-editor.org/rfc/rfc5789.html) — RFC Editor / Internet Engineering Task Force ## Primary reference - Name: RFC 5789 — PATCH Method for HTTP - Authority: www.rfc-editor.org - URL: https://www.rfc-editor.org/rfc/rfc5789.html - Source publication date: Not stated by the source ## Citation and use Preferred citation: “Require patch-format support before applying a partial resource change,” DSE Security, https://update.dsesecurity.com/updates/require-patch-format-support-before-applying-a-partial-resource-change/ Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/ Usage and citation policy: https://update.dsesecurity.com/usage/ Copyright © 2026 Detection Systems & Engineering. All rights reserved.