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CVE-2021-45960

HighCVSS 8.8 / 10
Published Jan 1, 2022·Last modified Apr 16, 2026
Affected Components(47)
libexpat/libexpat
V19990425
libexpat/libexpat
V19990709
libexpat/libexpat
R_2_0_1
1 / 16
Description

In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

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Risk Scores
Base Score
8.8

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a high impact on the availability of the system.

Threat Intelligence
8.3

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
4.23%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Proof of Concept

A proof of concept is available for this vulnerability (2 exploits found).

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