# CVE-2025-69873: ajv has ReDoS when using `$data` option > Attackers can cause denial of service via catastrophic backtracking in ajv when the $data option is enabled, requiring an upgrade to fix. - **Severity:** Low 2.9 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 11 Feb 2026 - **Updated:** 14 Sep 2026 - **Also known as:** CLEANSTART-2026-LI51874, CLEANSTART-2026-NS67921, CLEANSTART-2026-VM51396, CLSA-2026-1773015259, CLSA-2026-1773015260, CLSA-2026-1773015261, CLSA-2026-1774570946, CLSA-2026-1774916723, CLSA-2026-1775003172, CLSA-2026-1776818196, CLSA-2026-1779151627, CLSA-2026-1779151633, CLSA-2026-1787001707, CLSA-2026-1790161390, CLSA-2026-1790763286, CLSA-2026-1792488470, CLSA-2026-1792766110, CLSA-2026-1793046415, CLSA-2026-1793097555, DEBIAN-CVE-2025-69873, ECHO-c323-b788-63cc, GHSA-2g4f-4pwh-qvx6, MINI-2gwc-jxv7-h24v, MINI-448w-f589-rg5h, MINI-4crg-6wjr-x62f, MINI-5xx9-4jrq-8jmc, MINI-6622-wmw4-rf96, MINI-6c7m-qxj8-5pcr, MINI-6xr3-26qw-q3mg, MINI-747g-rw5m-wpm5, MINI-78rc-7x4w-xrfx, MINI-7v47-cp6c-6q28, MINI-7vxw-945h-56cg, MINI-c5hp-x8pj-g848, MINI-c7wg-797g-5q9q, MINI-cpjw-97vr-8v5f, MINI-f3hg-8pmh-hfgj, MINI-g4wm-hx7q-h67w, MINI-gp8g-hgmr-2h58, MINI-hc68-49vj-v2mr, MINI-jvwf-gm26-627g, MINI-p2m7-mqwj-2h6w, MINI-p4r6-6xg7-j9m4, MINI-pwgr-46qq-76rh, MINI-q4g2-jv69-5r8w, MINI-qg7m-g97f-x8pm, MINI-qj6g-7h42-xf34, MINI-vqgh-hhrm-4x6p, MINI-w66h-h363-6wmx, ROOT-APP-NPM-CVE-2025-69873, UBUNTU-CVE-2025-69873 ## What is CVE-2025-69873? CVE-2025-69873 is a low-severity denial of service vulnerability in ajv.js ajv, published on 11 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description ajv (Another JSON Schema Validator) before 8.18.0 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., "^(a|a)*$") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation. This issue is also fixed in version 6.14.0. Weakness: CWE-400 (Uncontrolled Resource Consumption), CWE-1333 (Inefficient Regular Expression Complexity) ## Which versions are affected by CVE-2025-69873? 4 open source packages ship an affected version, including ajv. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `ajv` | npm | All versions | 6.14.0 | | `ajv` | npm | All versions | 6.14.0 | | `ajv` | npm | From 7.0.0-alpha.0 | 8.18.0 | | `ajv` | npm | From 7.0.0-alpha.0 | 8.18.0 | ## How do I fix CVE-2025-69873? Upgrade ajv to a fixed version for your release line: 6.14.0 or 8.18.0. ## Is CVE-2025-69873 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-69873 exists. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-69873 and fix it if it is affected. What it is: CVE-2025-69873 is a low-severity denial of service vulnerability in ajv.js ajv, published on 11 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-69873 exists. Affected packages and fixed versions: - ajv (npm): affected all versions; fixed in 6.14.0 - ajv (npm): affected all versions; fixed in 6.14.0 - ajv (npm): affected from 7.0.0-alpha.0; fixed in 8.18.0 - ajv (npm): affected from 7.0.0-alpha.0; fixed in 8.18.0 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-69873/ (Markdown: https://insights.sbomify.com/CVE-2025-69873/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-69873 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-69873 - OSV: https://osv.dev/vulnerability/CVE-2025-69873 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-69873/ Summaries are generated and may contain mistakes; the official description above is the record.