Tornado versions before 6.5.9 contain an unbounded memory accumulation vulnerability in CurlAsyncHTTPClient that allows remote attackers to cause denial of service by sending a compressed response. Attackers can send a gzip-encoded decompression bomb that accumulates in memory without size limits, causing the application process to be killed by out-of-memory conditions.
CVE-2026-103262
HIGHPre-NVD 7.57.5—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-10-01. A secondary CVSS source baseline 7.5; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 7.5Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHhigh confidence
- EG Risk
- 38EG Risk 38/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation1% × 40%Automatability30% × 15%CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.5%
- EPSS %ILE
- 42nd
- KEV
- Not listed
CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 1, 2026
Last Modified
October 1, 2026
Advisory Details (3)
Auto-updated Oct 1, 2026🔬 Proof of concept available. Patch available. Sources: github, github_commit.
generic
Tornado before 6.5.9 Denial of Service via CurlAsyncHTTPClient | Advisories | VulnCheck
https://www.vulncheck.com/advisories/tornado-before-6.5.9-denial-of-service-via-curlasynchttpclientgithub_commit
commit e412435febba (tornadoweb/tornado)
Fix landed in tornadoweb/tornado commit e412435febba — awaiting tagged release
https://github.com/tornadoweb/tornado/commit/e412435febba4569c552c5c9054f1bf92bd171a9github Patch Available🟡 PoC Available
tornado: CurlAsyncHTTPClient enforces no response-size limit — decompression bomb drives unbounded memory accumulation to OOM (CWE-400, CWE-409) · Advisory · tornadoweb/tornado · GitHub
https://github.com/tornadoweb/tornado/security/advisories/GHSA-chx6-46f5-w4vpVendor Advisories for CVE-2026-103262(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 12× in last 7d / 12× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-04 04:11 UTCGHSA enrichment
- 2026-10-03 15:15 UTCEG score recompute
- 2026-10-03 15:14 UTCGHSA enrichment
- 2026-10-03 14:25 UTCEPSS rescore
- 2026-10-03 02:18 UTCEG score recompute
- 2026-10-03 02:17 UTCGHSA enrichment
- 2026-10-02 13:20 UTCGHSA enrichment
- 2026-10-02 00:23 UTCEG score recompute
- 2026-10-02 00:23 UTCGHSA enrichment
- 2026-10-01 11:27 UTCEG score recompute
- 2026-10-01 10:51 UTCEG score recompute
- 2026-10-01 10:50 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-103262?
CVE-2026-103262 is a high vulnerability published on October 1, 2026. Tornado versions before 6.5.9 contain an unbounded memory accumulation vulnerability in CurlAsyncHTTPClient that allows remote attackers to cause denial of service by sending a compressed response. Attackers can send a gzip-encoded decompression bomb that accumulates in memory without size limits,…
When was CVE-2026-103262 disclosed?
CVE-2026-103262 was first published on October 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-103262 actively exploited?
CVE-2026-103262 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (42nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-103262?
CVE-2026-103262 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-103262?
A fix for CVE-2026-103262 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-103262 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-103262
Is Your Infrastructure Affected by CVE-2026-103262?
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