How severe is CVE-2021-31317?

CVE-2021-31317 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-31317 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31317?

CVE-2021-31317 primarily affects Telegram. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-31317?

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

When was CVE-2021-31317 published?

CVE-2021-31317 was published on 2021-05-18 and last updated on 2026-06-17.

CVE-2021-31317

Q: What is CVE-2021-31317?

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type Confusion in the VDasher constructor of their custom fork of the rlottie library. A remote attacker might be able to access Telegram's heap memory out-of-bounds on a victim device via a malicious animated sticker.

CVE-2021-31317 is a medium-severity vulnerability in Telegram with a CVSS 3.x base score of 5.5. 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-843.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-843
Affected product: Telegram
Published: 2021-05-18
Last modified: 2026-06-17

Description

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type Confusion in the VDasher constructor of their custom fork of the rlottie library. A remote attacker might be able to access Telegram's heap memory out-of-bounds on a victim device via a malicious animated sticker.

Frequently asked questions

What is CVE-2021-31317?: Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Type Confusion in the VDasher constructor of their custom fork of the rlottie library. A remote attacker might be able to access Telegram's heap memory out-of-bounds on a victim device via a malicious animated sticker.
How severe is CVE-2021-31317?: CVE-2021-31317 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-31317 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31317?: CVE-2021-31317 primarily affects Telegram. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-31317?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-31317 published?: CVE-2021-31317 was published on 2021-05-18 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:telegram:telegram:*:*:*:*:*:android:*:*
cpe:2.3:a:telegram:telegram:*:*:*:*:*:iphone_os:*:*
cpe:2.3:a:telegram:telegram:*:*:*:*:*:macos:*:*

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