CVE-2026-82737

Ash.Vector wraps the 16-bit dimension header for vectors over 65,535 elements, corrupting data and crashing reads

MEDIUM
5.9
CVSS Score
Published: September 1, 2026 at 03:24 AM UTC
Updated: September 1, 2026 at 09:31 PM UTC
1 product affected across 1 vendorAsh

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

Integer Overflow or Wraparound vulnerability in ash-project ash lets an attacker corrupt a stored vector and crash later reads of it by submitting a vector with more than 65,535 elements. Ash.Vector.new/1 (lib/ash/vector.ex) encodes a vector as <<dim::unsigned-16, 0::unsigned-16>> followed by the element floats, packing the element count into a 16-bit field without checking its range. A list of more than 65,535 elements wraps the dimension modulo 65,536, so the encoded header records a dimension that disagrees with the number of stored floats. from_binary/1 later reads binary-size(dim)-unit(32) from the wrapped header, so every read of the corrupted value misparses and raises, denying access to the affected record. The fix rejects any vector whose dimension exceeds 65,535. This issue affects ash: from 2.14.13 before 3.32.2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

90%
2.14.13 ≤ v < 3.32.22.14.13e2855843ca4a9141dcd7f40f47227e13b43f0e00
Vendor states this is fixed in cef5eb7b0693f04d1699a36e02a4e09ce1e7bffe (fixed)
Affected range stops below 3.32.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMEEF
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-190

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