Issues

• MIP: false Optimal at gap 0 — HighsTransformedLp::untransform() drops tiny coefficients without relaxing the RHS, making a tableau cut invalid

  ERGO-Code/HiGHS#3434 · Filter by author DoumarCharles opened on Oct 17, 2026

• MIP incorrectly reported Optimal (28 vs feasible 19) with random_seed=15 and presolve enabled

  ERGO-Code/HiGHS#3433 · Filter by author rpalad opened on Oct 16, 2026

• LP: infeasible models end with Unknown / Solve error / Not Set on the default path; IPM says Infeasible

  BugLPSimplex
  ERGO-Code/HiGHS#3418 · Filter by author finik opened on Oct 14, 2026
  5

  

• Assertion errors from the Julia tests

  Code-qualityLP
  ERGO-Code/HiGHS#3413 · Filter by author odow opened on Oct 14, 2026
  

• MIP: a feasible, suboptimal user start (setSolution) is reported as Optimal, dual bound equal to its objective, with presolve on

  BugMIP
  ERGO-Code/HiGHS#3400 · Filter by author steggema opened on Oct 12, 2026
  3

  

• QP ASM issues

  BugQP ASMQP
  ERGO-Code/HiGHS#3396 · Filter by author jajhall opened on Oct 11, 2026
  

• Simplex issues

  BugLPSimplex
  ERGO-Code/HiGHS#3395 · Filter by author jajhall opened on Oct 11, 2026
  4

  

• Wrong Optimal 0 instead of 1 with presolve=off: analytic-center fixing of a continuous column

  ERGO-Code/HiGHS#3387 · Filter by author akatsukiwork0320 opened on Oct 9, 2026
  5

  

• Assertion error in model_status_ for trivial LP in MIP solve

  BugLP
  ERGO-Code/HiGHS#3383 · Filter by author Opt-Mucca opened on Oct 9, 2026
  2

  

• C API: solution from Highs_setCallbackSolution in the MIP user-solution callback is discarded

  MIP
  ERGO-Code/HiGHS#3381 · Filter by author DoumarCharles opened on Oct 9, 2026
  1

  

• highspy: get and set the basis as numpy arrays

  EnhancementPython
  ERGO-Code/HiGHS#3373 · Filter by author FBumann opened on Oct 7, 2026
  1

  

• Iteration after basis postsolve

  BugLPPresolve
  ERGO-Code/HiGHS#3362 · Filter by author jajhall opened on Oct 5, 2026
  

• Suspected: MIP time_limit not checked between presolve and B&B start (s100: 60 s → 258 s)

  Code-qualityMIP
  ERGO-Code/HiGHS#3314 · Filter by author berkorbay opened on Sep 24, 2026
  5

  

• Bugs in liftingForProbing

  BugMIPPresolve MIP
  ERGO-Code/HiGHS#3307 · Filter by author odow opened on Sep 21, 2026
  

• Feature request: pass sub-MIP solutions up to the parent MIP as they are found

  EnhancementMIP
  ERGO-Code/HiGHS#3304 · Filter by author spoorendonk opened on Sep 19, 2026
  2

  

• Sometimes hot start of LP problem results in wrong objective value

  Code-qualityLP
  ERGO-Code/HiGHS#3294 · Filter by author WinfriedL opened on Sep 16, 2026
  6

  

• Feature requests

  Enhancement
  ERGO-Code/HiGHS#3225 · Filter by author galabovaa opened on Aug 21, 2026
  

• Enhancements

  Enhancement
  ERGO-Code/HiGHS#3205 · Filter by author jajhall opened on Aug 6, 2026
  

• MIP: presolve fixes a column whose bounds are equal only within tolerance without bounding the objective error, returning a suboptimal solution as Optimal

  MIPPresolve MIP
  ERGO-Code/HiGHS#3173 · Filter by author EamonHetherton opened on Jul 27, 2026
  

• Member function in highspy has no effect

  BugPython
  ERGO-Code/HiGHS#3109 · Filter by author BenChampion opened on Jun 29, 2026
  4

  

• inconsistent docs for iis_strategy option

  Documentation
  ERGO-Code/HiGHS#3036 · Filter by author OrestisLomis opened on May 20, 2026
  

• segmentation fault using new pulp version (+rust) with latest highspy in Ubuntu

  Build
  ERGO-Code/HiGHS#2921 · Filter by author pchtsp opened on Mar 18, 2026
  4

  

• Feature request: Expose additional HiPO timing fields via HighsInfo

  EnhancementHiPOLP
  ERGO-Code/HiGHS#2910 · Filter by author MaykThewessen opened on Mar 12, 2026
  3

  

• Access violation with threads > 1 on Windows (highspy 1.13.1)

  BugMIPParallel
  ERGO-Code/HiGHS#2885 · Filter by author claudiabongiovanni opened on Mar 2, 2026
  

• MIP solver falsely reports kInfeasible on feasible models with wide coefficient ranges

  BugPresolve MIP
  ERGO-Code/HiGHS#2872 · Filter by author andy-moser opened on Feb 25, 2026
  7