Out-of-Bounds Read in rdiscount (CVE-2026-35201)
Summary
Vulnerability in rdiscount (CVE-2026-35201). Risk of unauthorized operations or information disclosure. Exploitable via INT_MAX. Mitigation: upgrade to 2.2.7.4 or later.
Original description
The description as published by the source.
Discount is an implementation of John Gruber's Markdown markup language in C. From 1.3.1.1 to before 2.2.7.4, a signed length truncation bug causes an out-of-bounds read in the default Markdown parse path. Inputs larger than INT_MAX are truncated to a signed int before entering the native parser, allowing the parser to read past the end of the supplied buffer and crash the process. This vulnerability is fixed in 2.2.7.4.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-35201 has been found in rdiscount.
Attackers can target a specific entry point like INT_MAX over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.9/10.
What to do: upgrade rdiscount to 2.2.7.4 or later.
If unsure, ask your IT team or search "rdiscount CVE-2026-35201" on the vendor's site.
CVE-2026-35201 (rdiscount) — CWE-125 / CVSS v3 5.9
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: INT_MAX / int / data / to_html
Patched: 2.2.7.4 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds read (CWE-125) exists in rdiscount. Attackers reach the vulnerable code path via INT_MAX without authentication.
Check the vendor advisory for the affected versions of rdiscount. Attack surface: INT_MAX / int / data / to_html.
Severity: Medium (CVSS 5.9/10). Risk of unauthorized operations or information disclosure.
Update to 2.2.7.4.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'rdiscount' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'rdiscount' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
rdiscountを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade rdiscount to 2.2.7.4ステージング環境で 2.2.7.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-35201 discount
- Ubuntu UBUNTU-CVE-2026-35201 discount
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com