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CVE-2026-16156

MEDIUM 5.1 PoC AVAILABLE

Published 2026-07-18 · Last modified 2026-07-21

A security flaw has been discovered in SourceCodester Class and Exam Timetabling System 1.0. This affects an unknown part of the file /forexam.php. The manipulation of the argument day results in cross site scripting. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks.

EXPLOIT AVAILABLE

Public exploit or PoC code exists. Modeled probability is still low, but the barrier to attack is reduced — watch closely.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 10th percentile

○ In CISA KEV ● Public exploit / PoC

Impact if exploited

5.1CVSS 4.0 · MEDIUM

  • ConfidentialityNone
  • IntegrityLow
  • AvailabilityNone

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ⚠Privileges: Requires a low-privilege account
  • ⚠User interaction: Succeeds with passive user activity
  • ✓Complexity: No special conditions — reliably repeatable
  • ✓Requirements: No special attack requirements

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-16156/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-16156/poc.json

Affected

Vendors Sourcecodester

Products Class And Exam Timetabling System

Weakness (CWE)

  • CWE-79: Cross Site Scripting
  • CWE-94: Code Injection

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

All CVSS metrics

  • MEDIUM 5.1 v4.0 · CNA Primary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
  • LOW 3.5 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R
  • LOW 3.5 v3.0 · CNA Primary
    CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R
  • MEDIUM 4 v2.0 · CNA Primary
    AV:N/AC:L/Au:S/C:N/I:P/A:N/E:POC/RL:ND/RC:UR
  • LOW 2 v4.0 · NVD Secondary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/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
  • LOW 3.5 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
  • MEDIUM 4 v2.0 · NVD Secondary
    AV:N/AC:L/Au:S/C:N/I:P/A:N

References

Exploits & PoC

Advisories

Technical & other

Sources: NVD · CVE.org · EPSS