Upx
CVE-2025-2849
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, buffer size validation
MITRE ATT&CK
2 techniques across 2 tactics: Execution, Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 4.8 (MEDIUM). Attack characteristics: local attack vector, low complexity, low privileges required, no user interaction not required. Public proof-of-concept exploit code is available. EPSS exploitation probability: 0.04%. |
| Exploit ScenarioDerived | A local attacker with access to the system could corrupt memory to execute arbitrary code or crash the application. |
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Alert meAnalysisAIv1 – Mar 28, 2026
A vulnerability, which was classified as problematic, was found in UPX up to 5.0.0. Rated medium severity (CVSS 4.8), this vulnerability is low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Use memory-safe languages or bounds-checking. Enable ASLR, DEP/NX, stack canaries. Use safe string functions.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Buffer Overflow (CWE-119), which allows attackers to corrupt memory to execute arbitrary code or crash the application. A vulnerability, which was classified as problematic, was found in UPX up to 5.0.0. Affected is the function PackLinuxElf64::un_DT_INIT of the file src/p_lx_elf.cpp. The manipulation leads to heap-based buffer overflow. It is possible to launch the attack on the local host. The exploit has been disclosed to the public and may be used. The patch is identified as e0b6ff192412f5bb5364c1948f4f6b27a0cd5ea2. It is recommended to apply a patch to fix this issue. Affected products include: Upx. Version information: up to 5.0.0..
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Primary rating from NVD.
CVSS VectorNVD
Lifecycle Timeline
3DescriptionCVE.org
A vulnerability, which was classified as problematic, was found in UPX up to 5.0.0. Affected is the function PackLinuxElf64::un_DT_INIT of the file src/p_lx_elf.cpp. The manipulation leads to heap-based buffer overflow. It is possible to launch the attack on the local host. The exploit has been disclosed to the public and may be used. The patch is identified as e0b6ff192412f5bb5364c1948f4f6b27a0cd5ea2. It is recommended to apply a patch to fix this issue.
Executive ViewAI
Organizations using UPX should be aware of moderate risk from CVE-2025-2849, a buffer overflow vulnerability rated CVSS 4.8. Exploitation could cause memory corruption or application crashes. Proof-of-concept code is publicly available. A patch is available and should be applied during regular vulnerability management.
Apply vendor patch. If patching is delayed: restrict network access and enable monitoring.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
Affected Products (CPE)CVE.org
A vulnerability was found in UPX up to 4.2.2. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploit
Null pointer dereference was found in upx PackLinuxElf::canUnpack() in p_lx_elf.cpp,in version UPX 4.0.0. Rated high sev
canUnpack in p_vmlinx.cpp in UPX 3.95 allows remote attackers to cause a denial of service (SEGV or buffer overflow, and
PackLinuxElf64::unpack in p_lx_elf.cpp in UPX 3.95 allows remote attackers to cause a denial of service (double free), l
A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. Rated medium severity (CVSS 6.6), this vulnerability is no
A Segmentation fault was found in UPX in PackLinuxElf64::invert_pt_dynamic() in p_lx_elf.cpp. Rated medium severity (CVS
A heap-based buffer overflow issue was discovered in UPX in PackTmt::pack() in p_tmt.cpp file. Rated medium severity (CV
An assertion abort was found in upx MemBuffer::alloc() in mem.cpp, in version UPX 4.0.0. Rated medium severity (CVSS 5.5
An invalid memory address dereference was discovered in the canUnpack function in p_mach.cpp in UPX 3.95 via a crafted M
A floating-point exception was discovered in PackLinuxElf::elf_hash in p_lx_elf.cpp in UPX 3.95. Rated medium severity (
A heap-based buffer over-read was discovered in canUnpack in p_mach.cpp in UPX 3.95 via a crafted Mach-O file. Rated med
An Integer overflow in the getElfSections function in p_vmlinx.cpp in UPX 3.95 allows remote attackers to cause a denial
Same weakness CWE-119 – Buffer Overflow
View allSame technique Buffer Overflow
View allVendor StatusVendor
SUSE
Severity: Low| Product | Status |
|---|---|
| openSUSE Leap 15.6 | Fixed |
| openSUSE Tumbleweed | Fixed |
Exploit-DB