CVE-2026-82672: medium-severity vulnerability in elixir-mint mint
Unvalidated chunk-size line tail in Mint HTTP/1 client enables response smuggling against strict intermediaries on pooled connections
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.3epss 0.5%
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in elixir-mint mint allows a malicious HTTP/1 server to desynchronize a strict intermediary and the Mint client on a pooled connection, enabling response-queue poisoning against subsequent requests that share the connection.
Mint.HTTP1.Parse.chunk_size/1 in lib/mint/http1/parse.ex stops at the first non-hexadecimal byte of a chunked response's chunk-size line and returns the remainder unexamined. Mint.HTTP1.decode_body/5 in lib/mint/http1.ex then discards every byte up to the CRLF with Parse.ignore_until_crlf/1, so the accepted grammar is a run of hex digits followed by arbitrary bytes, where RFC 9112 permits only a ;-introduced chunk extension. Lines such as 5ZZZZZ and 5 9 are accepted as chunk size 5, and 0ZZZZ is accepted as the terminating chunk that ends the message body. An RFC-strict intermediary rejects such a line while Mint accepts it, so the two disagree on chunk boundaries and on where the response ends.
This issue affects mint: from 0.1.0 before 1.10.1.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Affected products
elixir-mint · mintRelated CVEs — elixir-mint mint
In the same product, most dangerous first.
CVE-2026-82728HIGHUnbounded HTTP/1 status-line and chunk-extension buffering in Mint causes memory-exhaustion DoSEPSS 0.5%CVE-2026-82729MEDIUMQuadratic chunk-size parsing in Mint.HTTP1.Parse allows CPU-exhaustion DoSEPSS 0.5%CVE-2026-59249MEDIUMSign-tolerant HTTP/1 chunk-size parser in Mint enables response smuggling against strict intermediaries on pooled connectionsEPSS 0.5%CVE-2026-59246MEDIUMZero-length HTTP/2 CONTINUATION frames bypass Mint's header-block byte-size cap and exhaust client memoryEPSS 0.5%CVE-2026-58229HIGHUnbounded HTTP/1 response-header and chunked-trailer accumulation in Mint causes memory-exhaustion DoSEPSS 0.5%CVE-2026-56810HIGHmint buffers an entire chunked response chunk in memory in Mint.HTTP1.decode_body/5EPSS 0.4%
References
https://cna.erlef.org/cves/CVE-2026-82672.htmlhttps://github.com/elixir-mint/mint/commit/60089586ec7adc9fddb09f69a2f5919ba9ac7f33https://github.com/elixir-mint/mint/commit/c82377838dc6e275ef40bafa664fbcdf50270c60https://github.com/elixir-mint/mint/security/advisories/GHSA-rj5m-69wp-cxq9https://osv.dev/vulnerability/EEF-CVE-2026-82672