CVE WatchAug 15, 2026

CVE-2021-4034

Red Hat Polkit Out-of-Bounds Read and Write Vulnerability

CVSS

7.8

High

EPSS

94.9%

p100

KEV

YES

Jun 27, 2022

Exploit Today

0-100

Published: Jan 28, 2022 · Last modified: Aug 15, 2026 · CWE-787 · CWE-125

EPSS · 30d

94.9%EPSS · 30 days94.9%

2026-08-022026-08-30

KEV catalog record

Product

Red Hat / Polkit

Vulnerability

Red Hat Polkit Out-of-Bounds Read and Write Vulnerability

Added to KEV

Jun 27, 2022

Remediate by

Jul 18, 2022

Known ransomware use

Yes

Summary description

The Red Hat polkit pkexec utility contains an out-of-bounds read and write vulnerability that allows for privilege escalation with administrative rights.

Required action

Apply updates per vendor instructions.

Notes

https://nvd.nist.gov/vuln/detail/CVE-2021-4034

Technical description

A local privilege escalation vulnerability was found on polkit's pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn't handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it'll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-826087.4 HIG

—

———A vulnerability was determined in Kamailio up to 5.5.0/6.0.7. This affects the function get_4bytes of the file src/modules/ims_registrar_scscf/cxdx_avp.c of the component AVP Handler. Executing a manipulation can lead to out-of-bounds read. The attack may be performed from remote. The exploit has been publicly disclosed and may be utilized. This patch is called abb5d60af6eefbd367bf6588c5589566b090e272. It is advisable to implement a patch to correct this issue. The vendor points out, that "[v]ersion 5.5.0 is old and not maintained anymore."3h CVE-2026-823306.1 MED

2.0%

——1A flaw was found in the file-pvr plugin in GIMP. When processing a specially crafted PVR image file, the VQ (compressed) decoder does not properly perform memory bounds checking. This missing validation results in a heap out-of-bounds read. This issue can result in an application crash, leading to a denial of service or a limited information disclosure of heap memory contents.2d CVE-2026-823286.1 MED

1.9%

——1A flaw was found in the file-ico plugin in GIMP. When processing a specially crafted ICO image file, the plugin does not properly validate the used_clrs (palette count) parameter. This incorrect validation leads to improper memory bounds checking, resulting in a heap out-of-bounds read. This issue can result in an application crash, leading to a denial of service or a limited information disclosure of heap memory contents.2d CVE-2026-823246.1 MED

2.5%

——1A flaw was found in the file-iff (IFF/ILBM) plugin in GIMP. When processing a specially crafted IFF/ILBM image file, the plugin does not properly validate the HAM row size and improperly handles cases where the number of color planes (nPlanes) is zero. This causes a row size mismatch that bypasses memory bounds checking, resulting in heap out-of-bounds reads. This issue can result in an application crash, leading to a denial of service or a limited information disclosure of heap memory contents.2d CVE-2026-58106—

2.7%

——1CVE-2025-40843 https://github.com/advisories/GHSA-5xf2-f6ch-6p8r was fixed by replacing unchecked strcpy() with a bounded safe_strcpy() helper. At ldlogger-tool-gcc.c:129 the destination passed to that helper is fullPath + 2, but the size passed down is the full PATH_MAX. safe_strcpy() is strncpy(), which NUL-pads the destination out to the whole n, so this site writes 4096 bytes into the 4094 that remain — a 2-byte stack overflow on every invocation, independent of the input path's length. This issue affects CodeChecker: through 6.28.2.2d CVE-2026-400154.3 MED

21.1%

——6An attacker that has valid credentials can open many connections to the imap-hibernate service and send invalid commands, which can intermittently cause an out-of-bounds read and crash the process. The crash interrupts hibernated IMAP sessions handled by the affected process, which can cause degradation of service for IMAP. Disable IMAP hibernation. Update to non-vulnerable version. No publicly available exploits are known.3d