# CVE-2026-123616: imgproxy 3.3.0 before 4.0.16 Memory Exhaustion DoS via ICO Loader

Status: published. Published: 2026-11-08. Updated: 2026-11-08.

imgproxy from 3.3.0 before 4.0.16 contains an unbounded memory allocation vulnerability in the ICO loader that fails to validate the data_size field. Attackers can supply a crafted 23-byte ICO file declaring a ~4GB data_size to trigger memory exhaustion and worker crashes without authentication.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- imgproxy / imgproxy: ≥ 3.3.0; < 4.0.16 (affected, semver); 4.0.16 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-789

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/imgproxy/imgproxy/security/advisories/GHSA-mmq5-xm89-9pfg (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/imgproxy-3.3.0-before-4.0.16-memory-exhaustion-dos-via-ico-loader (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-123616; retrieved 2026-11-08; source updated 2026-11-08

Revision: 9da75580f45f2359e926fa02eef226d925c369a07242fe6cbd62d37bbfa85d4b

Canonical: https://y2.dev/cve/CVE-2026-123616

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