CVE-2026-62239

MEDIUMPre-NVD 6.66.6—
EchelonGraph scoreHIGH confidence

Score 6.6 from GitHub Security Advisory published 2026-07-14. a secondary CVSS source baseline 6.6; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
6.6
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.6Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

FlashAttention through 2.8.3.post1, fixed in commit 0816ef1, contains a symlink attack vulnerability in the download_and_copy() function within hopper/setup.py that extracts NVIDIA toolchain archives without validating symlinks or filtering tar members. A local attacker can pre-plant a symlink in the predictable cache directory to redirect extracted binaries to an attacker-chosen location, enabling arbitrary file write with victim privileges during build time.

CVSS v3
6.6
EG Score
6.6(high)
EG Risk
46(Track*)
EG Risk 46/100SSVC: Track*

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 computed
Severity66% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS
2.9%
KEV
Not listed

Published

July 13, 2026

Last Modified

July 15, 2026

Advisory Details (4)

Auto-updated Jul 13, 2026
🔬 Proof of concept available. Upstream fix merged — awaiting tagged release. Sources: github_pr, github_commit.
generic

FlashAttention Symlink Attack via tarfile.extractall in hopper/setup.py | Advisories | VulnCheck

https://www.vulncheck.com/advisories/flashattention-symlink-attack-via-tarfile-extractall-in-hopper-setup-py
github_commit

commit 0816ef12f424 (Dao-AILab/flash-attention)

Fix landed in Dao-AILab/flash-attention commit 0816ef12f424 — awaiting tagged release

https://github.com/Dao-AILab/flash-attention/commit/0816ef12f424c6ec94b057a72c275b14f6e6edb2
github_pr

hopper/setup.py: harden tarfile extraction against path traversal and symlink escape

Fix merged in Dao-AILab/flash-attention PR #2702 on 2026-07-12 — awaiting tagged release

https://github.com/Dao-AILab/flash-attention/pull/2702
generic🟡 PoC Available

Bare tarfile.extractall into Predictable Cache During Build in flash-attention · Issue #2637 · Dao-AILab/flash-attention · GitHub

https://github.com/Dao-AILab/flash-attention/issues/2637

Vendor Advisories for CVE-2026-62239(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 11× in last 7d / 20× 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.

  1. 2026-07-23 14:18 UTCEPSS rescore
  2. 2026-07-23 14:18 UTCEPSS rescore
  3. 2026-07-23 03:21 UTCEG score recompute
  4. 2026-07-22 14:08 UTCEPSS rescore
  5. 2026-07-22 14:08 UTCEPSS rescore
  6. 2026-07-21 15:25 UTCEPSS rescore
  7. 2026-07-21 15:25 UTCEPSS rescore
  8. 2026-07-20 17:08 UTCEPSS rescore
  9. 2026-07-19 14:31 UTCEPSS rescore
  10. 2026-07-19 02:29 UTCEPSS rescore
  11. 2026-07-18 10:04 UTCEPSS rescore
  12. 2026-07-16 23:00 UTCGHSA enrichment
  13. 2026-07-16 17:03 UTCEPSS rescore
  14. 2026-07-15 22:28 UTCGHSA enrichment
  15. 2026-07-15 16:57 UTCEPSS rescore
  16. 2026-07-15 02:00 UTCEPSS rescore
  17. 2026-07-15 02:00 UTCEPSS rescore
  18. 2026-07-14 21:55 UTCGHSA enrichment
  19. 2026-07-13 21:23 UTCEG score recompute
  20. 2026-07-13 21:22 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-62239?
CVE-2026-62239 is a medium vulnerability published on July 13, 2026. FlashAttention through 2.8.3.post1, fixed in commit 0816ef1, contains a symlink attack vulnerability in the downloadandcopy() function within hopper/setup.py that extracts NVIDIA toolchain archives without validating symlinks or filtering tar members. A local attacker can pre-plant a symlink in the…
When was CVE-2026-62239 disclosed?
CVE-2026-62239 was first published in the National Vulnerability Database on July 13, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-62239 actively exploited?
CVE-2026-62239 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-62239?
CVE-2026-62239 has a CVSS v3 base score of 6.6 (NVD).
How do I remediate CVE-2026-62239?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-62239, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-62239

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