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Medium · 6.3 CVE-2026-70409 EUVD-2026-69247

eldap does not bound the port component of a referral URL before integer conversion

Published Sep 1, 2026 · Updated Nov 11, 2026 · Assigned by EEF

Description

Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP eldap allows a malicious or compromised LDAP server to degrade availability by returning a referral URL whose port component is a very long run of digits.

eldap:parse_port/2 passes the port substring straight to list_to_integer/1 with no length bound. The surrounding try ... catch only rejects a value that fails to parse, so a syntactically valid port of up to roughly 1.26 million digits converts successfully and costs the caller hundreds of milliseconds of arbitrary-precision arithmetic per referral. The conversion function itself is documented to accept integers of any size, so bounding the input is the caller's responsibility. Reaching the flaw requires the application to pass a server-supplied referral to eldap:parse_ldap_url/1, which eldap never calls itself: referral strings are returned to the caller unparsed.

This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, OTP 28.5.0.6, and OTP 29.0.6, corresponding to eldap from 1.0.3 before 1.2.14.2, 1.2.16.1, and 1.3.1.

Affected products

VendorProductAffectedFixed
Erlang OTP 17.0, 1.0.3 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 erlang 1:29.0.6+dfsg-1 —
Debian 13 erlang 1:27.3.4.1+dfsg-1+deb13u4 —
Debian 12 erlang No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.04 LTS erlang 1:27.3.4.6+dfsg-1ubuntu0.1 —
Ubuntu 24.04 LTS erlang 1:25.3.2.8+dfsg-1ubuntu4.7 —
Ubuntu 22.04 LTS erlang 1:24.2.1+dfsg-1ubuntu0.7 —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 20.04 LTS erlang 1:22.2.7+dfsg-1ubuntu0.5+esm2 —
Ubuntu Pro 18.04 LTS erlang 1:20.2.2+dfsg-1ubuntu2+esm3 —
Ubuntu Pro 16.04 LTS erlang 1:18.3-dfsg-1ubuntu3.1+esm3 —
Ubuntu Pro 14.04 LTS erlang 1:16.b.3-dfsg-1ubuntu2.2+esm2 —
ReleasePackageFixed inAdvisory
Red Hat Hardened Images 1 erlang27 +38 27.3.4.17-0.1.hum1 RHSA-2026:62531

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 erlang 26.2.5.21-6 —

Advisories 2

References