CVSS 4.0
8.7 highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NCVE-2026-128242 actix-http before 3.20.1 and actix-web before 4.18.2 Decompression Bomb DoS via encoding::Decoder
High (8.7) in actix. EPSS 1.0% estimated probability of exploitation activity in the next 30 days.
On this page
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.
Severity
CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- EPSS
- 1.0% estimated probability of exploitation activity in the next 30 days; 62nd percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: yes · Technical impact: partial, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)
- Published
- Modified
- Assigned by
- VulnCheck (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| actix-http | before 3.20.1 |
| actix-web | before 4.18.2 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Ubuntu | 26.04:LTS, 26.10 | rust-actix-http | no fix listed | UBUNTU-CVE-2026-128242 |
From the distributions' data via OSV.dev: Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Ubuntu.
References
- https://github.com/actix/actix-web
- https://github.com/actix/actix-web/blob/actix-http-v3.20.0/actix-http/src/encoding/decoder.rs#L239-L301
- https://github.com/actix/actix-web/commit/0d0be61bd757027bfcecbc53df1b7a600f21ecd0
- https://github.com/actix/actix-web/commit/41b54d23ea04f66758c15de7e4ab18325cd25280
- https://github.com/actix/actix-web/releases/tag/actix-http-v3.20.1
- https://github.com/actix/actix-web/releases/tag/actix-web-v4.18.2
- https://github.com/actix/actix-web/security/advisories/GHSA-qph8-7859-gq2f
- https://rustsec.org/advisories/RUSTSEC-2026-0448.html
- https://www.vulncheck.com/advisories/actix-http-before-3.20.1-and-actix-web-before-4.18.2-decompression-bomb-dos-via-encoding-decoder