How severe is CVE-2021-30496?

CVE-2021-30496 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-30496 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30496?

CVE-2021-30496 affects Telegram. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-30496?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-30496 published?

CVE-2021-30496 was published on 2021-04-20 and last updated on 2026-06-17.

CVE-2021-30496

CVE-2021-30496 is a medium-severity vulnerability in Telegram with a CVSS 3.x base score of 5.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-121.

Key facts

Severity: Medium (CVSS 3.x base score 5.7)
CVSS v2: 3.5
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-121
Affected product: Telegram
Published: 2021-04-20
Last modified: 2026-06-17

Description

The Telegram app 7.6.2 for iOS allows remote authenticated users to cause a denial of service (application crash) if the victim pastes an attacker-supplied message (e.g., in the Persian language) into a channel or group. The crash occurs in MtProtoKitFramework. NOTE: the vendor's perspective is that "this behavior can't be considered a vulnerability."

Frequently asked questions

What is CVE-2021-30496?: The Telegram app 7.6.2 for iOS allows remote authenticated users to cause a denial of service (application crash) if the victim pastes an attacker-supplied message (e.g., in the Persian language) into a channel or group. The crash occurs in MtProtoKitFramework. NOTE: the vendor's perspective is that "this behavior can't be considered a vulnerability."
How severe is CVE-2021-30496?: CVE-2021-30496 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-30496 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30496?: CVE-2021-30496 affects Telegram. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-30496?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-30496 published?: CVE-2021-30496 was published on 2021-04-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:telegram:telegram:7.6.2:*:*:*:*:iphone_os:*:*

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