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CVE-2025-59038NVD status: Deferred

Prebid.js: Embedded Malicious Code

CVE-2025-59038 is a high-severity embedded malicious code vulnerability in Prebid.js from Prebid, with a CVSS 4.0 base score of 8.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected Prebid.js versions: = 10.9.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Prebid.js you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
PrebidPrebid.js= 10.9.2Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
ActiveA user must deliberately do something unusual, such as dismissing a warning.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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. Scored by CNA (github.com).

Official description

Prebid.js is a free and open source library for publishers to quickly implement header bidding. NPM users of prebid 10.9.2 may have been briefly compromised by a malware campaign. The malicious code attempts to redirect crypto transactions on the site to the attackers' wallet. Version 10.10.0 fixes the issue. As a workaround, it is also possible to downgrade to 10.9.1.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Embedded Malicious Code

The product contains code that appears to be malicious in nature.

How developers prevent this class of flaw

  • Remove the malicious code and start an effort to ensure that no more malicious code exists. This may require a detailed review of all code, as it is possible to hide a serious attack in only one or two lines of code. These lines may be located almost anywhere in an application and may have been intentionally obfuscated by the attacker.

More Embedded Malicious Code vulnerabilities (CWE-506)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Embedded Malicious Code vulnerabilities

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