5.9

CVSS Score

4.0

-

CVSS Score

Basic Information

Concerned about an active attack path?

Talk to our security experts and see Miggo in action.

Miggo Vulnerability Database

→

CVE-2026-24738

CVE-2026-24738: gmrtd ReadFile Vulnerable to Denial of Service via Excessive TLV Length Values

gmrtd is a Go library for reading Machine Readable Travel Documents (MRTDs). Prior to version 0.17.2, ReadFile accepts TLVs with lengths that can range up to 4GB, which can cause unconstrained resource consumption in both memory and cpu cycles. ReadFile can consume an extended TLV with lengths well outside what would be available in ICs. It can accept something all the way up to 4GB which would take too many iterations in 256 byte chunks, and would also try to allocate memory that might not be available in constrained environments like phones. Or if an API sends data to ReadFile, the same problem applies. The very small chunked read also locks the goroutine in accepting data for a very large number of iterations. projects using the gmrtd library to read files from NFCs can experience extreme slowdowns or memory consumption. A malicious NFC can just behave like the mock transceiver described above and by just sending dummy bytes as each chunk to be read, can make the receiving thread unresponsive and fill up memory on the host system. Version 0.17.2 patches the issue.

(GitHub Advisory)

Miggo Vulnerability Database

→

CVE-2026-24738

CVE-2026-24738:

5.9

CVSS Score

4.0

-

CVSS Score

Basic Information

Is this CVE running in your environment?

Easily map the attack path and prioritize which CVEs are a threat to your organization

Validate Exposure

Technical Details

Package Name	Ecosystem	Vulnerable Versions	First Patched Version
github.com/gmrtd/gmrtd	go	< 0.17.2	0.17.2

Technical Details

Vulnerability Intelligence
Miggo AI

Root Cause Analysis

The analysis of the security advisory and the associated commit 54469a95e5a20a8602ac1457b2110bfeb80c8891 confirms that the vulnerability lies within the gmrtd/gmrtd library's handling of file reads from NFC sources. The root cause of the CVE is the lack of input validation on the length field of BER-TLV encoded data in the ReadFile function. A malicious or non-compliant NFC device could specify a very large file length (up to 4GB), causing the ReadFile function to enter a resource-intensive loop, attempting to read an enormous file. This leads to excessive CPU and memory usage, resulting in a denial of service.

The primary vulnerable function is NfcSession.ReadFile located in iso7816/nfc_session.go. The patch directly addresses the vulnerability by introducing two key checks: one to enforce a maximum allowable TLV length (readFileMaxTlvLength) and another to limit the number of read iterations (readFileMaxChunks).

Additionally, the NfcSession.ReadBinaryFromOffset function, which is utilized by ReadFile, was also patched. This function now verifies that the data received from the transceiver does not exceed the requested length, providing an additional layer of defense against abnormal responses from the NFC source. Both functions would appear in a runtime profile during an exploit scenario.

Vulnerable functions

NfcSession.ReadFile

iso7816/nfc_session.go

The `ReadFile` function was vulnerable to a denial of service. It processes BER-TLV encoded data from an NFC source. Prior to the patch, the function did not validate the length field from the TLV data. A malicious source could provide an excessively large length, causing the function to attempt to allocate a huge amount of memory and perform a vast number of read operations, leading to resource exhaustion and a denial of service. The patch introduces checks to limit the maximum allowed TLV length and the maximum number of read chunks.

NfcSession.ReadBinaryFromOffset

iso7816/nfc_session.go

This function is called by `ReadFile` to read binary data from a specific offset. The patch added a check to ensure that the amount of data returned by the transceiver does not exceed the amount that was requested. This prevents a malicious transceiver from sending an unexpectedly large payload in response to a read command, which could also contribute to a denial of service condition by causing unexpected memory allocation.

Vulnerability Intelligence
Miggo AI

Unlock WAF rules for this CVE

Generate vendor-ready rules for the observed attack patterns, plus reasoning and safe deployment guidance

Get WAF rules

WAF Protection Rules

WAF Rule

W** rul*s *v*il**l* *or Mi**o *ustom*rs only.W** rul*s *v*il**l* *or Mi**o *ustom*rs only.W** rul*s *v*il**l* *or Mi**o *ustom*rs only.W** rul*s *v*il**l* *or Mi**o *ustom*rs only.W** rul*s *v*il**l* *or Mi**o *ustom*rs only.W** rul*s *v*il**l* *or Mi**o *ustom*rs only.W** rul*s *v*il**l* *or Mi**o *ustom*rs only.W** rul*s *v*il**l* *or Mi**o *ustom*rs only.W** rul*s *v*il**l* *or Mi**o *ustom*rs only.W** rul*s *v*il**l* *or Mi**o *ustom*rs only.

Reasoning

*v*il**l* *or Mi**o *ustom*rs only.*v*il**l* *or Mi**o *ustom*rs only.*v*il**l* *or Mi**o *ustom*rs only.*v*il**l* *or Mi**o *ustom*rs only.*v*il**l* *or Mi**o *ustom*rs only.*v*il**l* *or Mi**o *ustom*rs only.*v*il**l* *or Mi**o *ustom*rs only.*v*il**l* *or Mi**o *ustom*rs only.*v*il**l* *or Mi**o *ustom*rs only.*v*il**l* *or Mi**o *ustom*rs only.