8.7
HIGH CVSS 4.0
CVE-2026-128242
actix-http before 3.20.1 and actix-web before 4.18.2 Decompression Bomb DoS via encoding::Decoder
Description

actix-http before 3.20.1 and actix-web before 4.18.2 contain an unbounded decompression vulnerability in encoding::Decoder that lets remote attackers exhaust memory and CPU via compressed bodies. Attackers can send small highly compressed gzip, deflate, Brotli or zstd request bodies to Json, Form, Bytes or String extractors, or serve them to awc clients, causing denial of service.

INFO

Published Date :

Nov. 13, 2026, 10:18 a.m.

Last Modified :

Nov. 13, 2026, 10:18 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-128242 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Actix actix-http
2 Actix actix-web
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 HIGH MITRE-CVE
CVSS 3.1 HIGH [email protected]
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Update actix-http and actix-web to patch denial-of-service vulnerability.
  • Update actix-http to version 3.20.1 or later.
  • Update actix-web to version 4.18.2 or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-128242 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-128242 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-128242 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-128242 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Nov. 13, 2026

    Action Type Old Value New Value
    Added Description actix-http before 3.20.1 and actix-web before 4.18.2 contain an unbounded decompression vulnerability in encoding::Decoder that lets remote attackers exhaust memory and CPU via compressed bodies. Attackers can send small highly compressed gzip, deflate, Brotli or zstd request bodies to Json, Form, Bytes or String extractors, or serve them to awc clients, causing denial of service.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-409
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/128xxx/CVE-2026-128242.json">CVE-2026-128242</a>
    Added Reference https://github.com/actix/actix-web
    Added Reference https://github.com/actix/actix-web/blob/actix-http-v3.20.0/actix-http/src/encoding/decoder.rs#L239-L301
    Added Reference https://github.com/actix/actix-web/commit/0d0be61bd757027bfcecbc53df1b7a600f21ecd0
    Added Reference https://github.com/actix/actix-web/commit/41b54d23ea04f66758c15de7e4ab18325cd25280
    Added Reference https://github.com/actix/actix-web/releases/tag/actix-http-v3.20.1
    Added Reference https://github.com/actix/actix-web/releases/tag/actix-web-v4.18.2
    Added Reference https://github.com/actix/actix-web/security/advisories/GHSA-qph8-7859-gq2f
    Added Reference https://rustsec.org/advisories/RUSTSEC-2026-0448.html
    Added Reference https://www.vulncheck.com/advisories/actix-http-before-3.20.1-and-actix-web-before-4.18.2-decompression-bomb-dos-via-encoding-decoder
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.