Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS
CVE-2026-120435 Overview
Netpbm before 10.86.51, 11.x before 11.02.30, and 11.03 before 11.15.08 contains a heap buffer overflow in xpmtoppm caused by an unvalidated characters-per-pixel value in the XPM header. Attackers can supply a crafted XPM file with characters-per-pixel greater than 3 to overrun fixed 3-byte colorName hash entries, causing crashes or potentially code execution.
Critical Impact
Affected Products
- Netpbm: see the vendor advisory for the exact affected versions
Discovery Timeline
- 2026-11-02: CVE-2026-120435 published to the National Vulnerability Database by disclosure@vulncheck.com
- 2026-11-02: last updated in the NVD database
Technical Details for CVE-2026-120435
Vulnerability Analysis
CVE-2026-120435 is a Out of Bounds Write weakness (CWE-787: Out of Bounds Write) in Netpbm. Based on its CVSS vector, the flaw needs local or adjacent access, needs no login, and relies on a user taking an action. The program writes past the end of a buffer, a common path to code execution.
With a CVSS base score of 8.5, apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Root Cause
The weakness is classified as CWE-787: Out of Bounds Write. The program writes past the end of a buffer, a common path to code execution.
Attack Vector
Based on the CVSS vector, the flaw needs local or adjacent access, needs no login, and relies on a user taking an action. Attack complexity is low complexity.
No exploitation in the wild is confirmed by CISA at the time of the last update. Check the references below for any vendor or researcher proof of concept.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Detection Methods for CVE-2026-120435
Detection Strategies
- Inventory every instance of Netpbm and compare the running version with the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Run an authenticated vulnerability scan once your scanner ships a check for this CVE.
Monitoring Recommendations
- Forward Netpbm application, access and audit logs to your SIEM for retrospective hunting.
- Alert on new processes, configuration changes or outbound connections from the affected service.
- Track the vendor advisory and the CISA KEV catalog for changes in exploitation status.
How to Mitigate CVE-2026-120435
Immediate Actions Required
- Apply the fixed version of Netpbm named in the vendor advisory.
- Prioritize internet facing and business critical instances first.
- Rescan after the change to confirm the exposure is closed.
Patch Information
Use the fixed version listed in the vendor advisory for Netpbm.
Workarounds
- If patching must wait, restrict network access to the affected service and place it behind authentication or a web application firewall rule.
CWE References
- CWE-787: Out of Bounds Write More CVEs with this weakness
Technical References
This entry is built directly from NVD, CISA KEV and EPSS data. Verify fixed versions in the vendor advisory before you deploy.
Frequently asked questions
Related CVEs
Out-of-bounds Write, Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in azerothcore azerothcore-wotlk (deps/zlib modules). This vulnerability is associated with program files inflate.C. This issue affects azerothcore-wotlk: through v4.0.0.
There is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
Kitty is a cross-platform GPU based terminal. In versions 0.46.2 and below, the handle_compose_command() function in kitty/graphics.c performs bounds validation on composition offsets using unsigned 32-bit arithmetic that is subject to integer wrapping, potentially leading to Heap Buffer Over-Read/Write. An attacker who can write escape sequences to a kitty terminal (e.g., via a malicious file, SSH login banner, or piped content) can supply crafted x_offset/y_offset values that pass the bounds check after wrapping but cause massive out-of-bounds heap memory access in compose_rectangles(). No user interaction is required. No non-default configuration is required. The attacker only needs the ability to produce output in a kitty terminal window. This issue has been fixed in version 0.47.0.
In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: add bounds checks in nvmet_tcp_build_pdu_iovec nvmet_tcp_build_pdu_iovec() could walk past cmd->req.sg when a PDU length or offset exceeds sg_cnt and then use bogus sg->length/offset values, leading to _copy_to_iter() GPF/KASAN. Guard sg_idx, remaining entries, and sg->length/offset before building the bvec.
ALGO 8180 IP Audio Alerter InformaCast Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of ALGO 8180 IP Audio Alerter devices. Authentication is not required to exploit this vulnerability. The specific flaw exists within the InformaCast functionality. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the device. Was ZDI-CAN-28302.
ALGO 8180 IP Audio Alerter SIP INVITE Alert-Info Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of ALGO 8180 IP Audio Alerter devices. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of the Alert-Info header of SIP INVITE requests. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of the device. Was ZDI-CAN-28301.
Earn your free CTEM certification.
Learn to scope, prioritize, validate and mobilize fixes for CVEs like CVE-2026-120435 with a free CTEM certification.
Beginner / Practitioner / Program Leader
Explore certifications