Vodafone admitted Tuesday it found security flaws in Huawei's telecommunications equipment in 2011 and 2012, a revelation that could further stain the reputation of the Chinese tech giant.

U.K.-based Vodafone, the world's second-largest mobile operator, said in a statement it had found security vulnerabilities in Huawei technology supplied to its Italian business dating back to 2011. The vulnerabilities, which were first reported Tuesday by Bloomberg, have since been resolved, both companies confirmed to CNBC.

"The issues were identified by independent security testing, initiated by Vodafone as part of our routine security measures, and fixed at the time by Huawei," Vodafone said in a statement.

Vodafone said there is no evidence that Huawei gained "unauthorized access" to its networks, adding "this was nothing more than a failure to remove a diagnostic function after development."

"Software vulnerabilities are an industry-wide challenge," a Huawei spokesperson told CNBC. "Like every ICT vendor we have a well established public notification and patching process, and when a vulnerability is identified we work closely with our partners to take the appropriate corrective action."