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CVE-2026-71562

httpc does not bound server-supplied numeric header values before integer conversion PUBLISHED

Description (CNA)

Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP inets httpc allows a malicious or compromised HTTP server to degrade availability by returning a numeric header whose value is a very long run of digits. httpc_handler.erl converts the server-supplied Content-Length with list_to_integer/1 before comparing it against max_body_size, so the size check cannot protect the conversion, and the option defaults to nolimit in any case. The same unbounded conversion appears in httpc_response:format_response/1 for Content-Length and in httpc_response:get_ms_from_retry_after/1 for Retry-After, which is guarded only by a check that the first character is a digit. A value of up to roughly 1.26 million digits converts successfully and costs the requesting process hundreds of milliseconds of arbitrary-precision arithmetic per response. The conversion function is documented to accept integers of any size, so bounding the input is the caller's responsibility. 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.

Affected (CNA)

Vendor / productVersions
Erlang / OTPunknown 0 before 17.0; affected 17.0 before 27.3.4.17; affected 28.0 before 28.5.0.6; affected 29.0 before 29.0.6
Erlang / OTPunknown 0 before 5.10; affected 5.10 before 9.3.2.7; affected 9.4 before 9.6.2.3; affected 9.7 before 9.7.2
Erlang / OTPaffected 84adefa331c4159d432d22840663c38f155cd4c1 before *

CWE

CWE-1284

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.