CVE-2026-73270: high-severity vulnerability in Erlang OTP
httpd mod_auth directory protection bypassed by request path casing on case-insensitive filesystems
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.2epss 0.9%
Improper Handling of Case Sensitivity vulnerability in Erlang/OTP inets httpd allows a remote unauthenticated attacker to read files inside a mod_auth protected directory by requesting them with different casing, on deployments whose filesystem is case-insensitive.
mod_auth:secret_path/3 decides whether a resolved filesystem path lies inside a protected directory block by running the configured directory path through re:run/3 without the caseless option. A request for /secret/file against a directory configured as /Secret therefore does not match, so the request is treated as unprotected and no authentication challenge is issued, while the filesystem resolves the differently cased path to the same file and mod_get serves it. Deployments on case-sensitive filesystems are unaffected, because there the filesystem itself rejects the mismatched casing.
This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
Erlang · OTPRelated CVEs — Erlang OTP
In the same product, most dangerous first.
CVE-2026-66835HIGHhttpd mod_auth directory protection bypassed by a doubled slash in the request pathEPSS 1.0%CVE-2026-69664HIGHhttpd parks a request worker indefinitely on a malformed chunk size sent after the headersEPSS 0.9%CVE-2026-70399HIGHhttpd does not enforce the documented default max_clients connection limitEPSS 0.9%CVE-2026-75538HIGHA Signed Length Overflow in Erlang/OTP's inet TCP Driver Overflows the Receive Buffer Into BEAM VM Memory From an Unauthenticated PeerEPSS 0.9%CVE-2026-59250HIGHMegaco flex scanner buffer overflow via oversized property parm nameEPSS 0.8%CVE-2026-70405MEDIUMsnmp BER INTEGER decoder applies no size limit to attacker-supplied integer fieldsEPSS 0.7%
References
https://cna.erlef.org/cves/CVE-2026-73270.htmlhttps://github.com/erlang/otp/commit/9641944a2efbf55bea760f8ff7ba777fe3a0961chttps://github.com/erlang/otp/commit/bac19eb3dbd96cc49b6d8cabc1c04248bf8c79f6https://github.com/erlang/otp/commit/d8878dec0ececc2eab18e47bb18b472f224ca633https://github.com/erlang/otp/security/advisories/GHSA-mh78-93cr-jx8fhttps://osv.dev/vulnerability/EEF-CVE-2026-73270https://www.erlang.org/doc/system/versions.html#order-of-versions